Transformative, Mixed Methods Checklist for Psychological Research with Mexican Americans

ERIC Educational Resources Information Center

Canales, Genevieve

2013-01-01

This is a description of the creation of a research methods tool, the "Transformative, Mixed Methods Checklist for Psychological Research With Mexican Americans." For conducting literature reviews of and planning mixed methods studies with Mexican Americans, it contains evaluative criteria calling for transformative mixed methods, perspectives…

Using mixed methods research in medical education: basic guidelines for researchers.

PubMed

Schifferdecker, Karen E; Reed, Virginia A

2009-07-01

Mixed methods research involves the collection, analysis and integration of both qualitative and quantitative data in a single study. The benefits of a mixed methods approach are particularly evident when studying new questions or complex initiatives and interactions, which is often the case in medical education research. Basic guidelines for when to use mixed methods research and how to design a mixed methods study in medical education research are not readily available. The purpose of this paper is to remedy that situation by providing an overview of mixed methods research, research design models relevant for medical education research, examples of each research design model in medical education research, and basic guidelines for medical education researchers interested in mixed methods research. Mixed methods may prove superior in increasing the integrity and applicability of findings when studying new or complex initiatives and interactions in medical education research. They deserve an increased presence and recognition in medical education research.

Approaches to Mixed Methods Dissemination and Implementation Research: Methods, Strengths, Caveats, and Opportunities.

PubMed

Green, Carla A; Duan, Naihua; Gibbons, Robert D; Hoagwood, Kimberly E; Palinkas, Lawrence A; Wisdom, Jennifer P

2015-09-01

Limited translation of research into practice has prompted study of diffusion and implementation, and development of effective methods of encouraging adoption, dissemination and implementation. Mixed methods techniques offer approaches for assessing and addressing processes affecting implementation of evidence-based interventions. We describe common mixed methods approaches used in dissemination and implementation research, discuss strengths and limitations of mixed methods approaches to data collection, and suggest promising methods not yet widely used in implementation research. We review qualitative, quantitative, and hybrid approaches to mixed methods dissemination and implementation studies, and describe methods for integrating multiple methods to increase depth of understanding while improving reliability and validity of findings.

Approaches to Mixed Methods Dissemination and Implementation Research: Methods, Strengths, Caveats, and Opportunities

PubMed Central

Green, Carla A.; Duan, Naihua; Gibbons, Robert D.; Hoagwood, Kimberly E.; Palinkas, Lawrence A.; Wisdom, Jennifer P.

2015-01-01

Limited translation of research into practice has prompted study of diffusion and implementation, and development of effective methods of encouraging adoption, dissemination and implementation. Mixed methods techniques offer approaches for assessing and addressing processes affecting implementation of evidence-based interventions. We describe common mixed methods approaches used in dissemination and implementation research, discuss strengths and limitations of mixed methods approaches to data collection, and suggest promising methods not yet widely used in implementation research. We review qualitative, quantitative, and hybrid approaches to mixed methods dissemination and implementation studies, and describe methods for integrating multiple methods to increase depth of understanding while improving reliability and validity of findings. PMID:24722814

Mixed methods research in music therapy research.

PubMed

Bradt, Joke; Burns, Debra S; Creswell, John W

2013-01-01

Music therapists have an ethical and professional responsibility to provide the highest quality care possible to their patients. Much of the time, high quality care is guided by evidence-based practice standards that integrate the most current, available research in making decisions. Accordingly, music therapists need research that integrates multiple ways of knowing and forms of evidence. Mixed methods research holds great promise for facilitating such integration. At this time, there have not been any methodological articles published on mixed methods research in music therapy. The purpose of this article is to introduce mixed methods research as an approach to address research questions relevant to music therapy practice. This article describes the core characteristics of mixed methods research, considers paradigmatic issues related to this research approach, articulates major challenges in conducting mixed methods research, illustrates four basic designs, and provides criteria for evaluating the quality of mixed methods articles using examples of mixed methods research from the music therapy literature. Mixed methods research offers unique opportunities for strengthening the evidence base in music therapy. Recommendations are provided to ensure rigorous implementation of this research approach.

Addressing Research Design Problem in Mixed Methods Research

NASA Astrophysics Data System (ADS)

Alavi, Hamed; Hąbek, Patrycja

2016-03-01

Alongside other disciplines in social sciences, management researchers use mixed methods research more and more in conduct of their scientific investigations. Mixed methods approach can also be used in the field of production engineering. In comparison with traditional quantitative and qualitative research methods, reasons behind increasing popularity of mixed research method in management science can be traced in different factors. First of all, any particular discipline in management can be theoretically related to it. Second is that concurrent approach of mixed research method to inductive and deductive research logic provides researchers with opportunity to generate theory and test hypothesis in one study simultaneously. In addition, it provides a better justification for chosen method of investigation and higher validity for obtained answers to research questions. Despite increasing popularity of mixed research methods among management scholars, there is still need for a comprehensive approach to research design typology and process in mixed research method from the perspective of management science. The authors in this paper try to explain fundamental principles of mixed research method, its typology and different steps in its design process.

Using mixed methods effectively in prevention science: designs, procedures, and examples.

PubMed

Zhang, Wanqing; Watanabe-Galloway, Shinobu

2014-10-01

There is growing interest in using a combination of quantitative and qualitative methods to generate evidence about the effectiveness of health prevention, services, and intervention programs. With the emerging importance of mixed methods research across the social and health sciences, there has been an increased recognition of the value of using mixed methods for addressing research questions in different disciplines. We illustrate the mixed methods approach in prevention research, showing design procedures used in several published research articles. In this paper, we focused on two commonly used mixed methods designs: concurrent and sequential mixed methods designs. We discuss the types of mixed methods designs, the reasons for, and advantages of using a particular type of design, and the procedures of qualitative and quantitative data collection and integration. The studies reviewed in this paper show that the essence of qualitative research is to explore complex dynamic phenomena in prevention science, and the advantage of using mixed methods is that quantitative data can yield generalizable results and qualitative data can provide extensive insights. However, the emphasis of methodological rigor in a mixed methods application also requires considerable expertise in both qualitative and quantitative methods. Besides the necessary skills and effective interdisciplinary collaboration, this combined approach also requires an open-mindedness and reflection from the involved researchers.

A Mixed Methods Content Analysis of the Research Literature in Science Education

NASA Astrophysics Data System (ADS)

Schram, Asta B.

2014-10-01

In recent years, more and more researchers in science education have been turning to the practice of combining qualitative and quantitative methods in the same study. This approach of using mixed methods creates possibilities to study the various issues that science educators encounter in more depth. In this content analysis, I evaluated 18 studies from science education journals as they relate to the definition, design, and overall practice of using mixed methods. I scrutinized a purposeful sample, derived from 3 journals (the International Journal of Science Education, the Journal of Research in Science Teaching, and the Research in Science Education) in terms of the type of data collected, timing, priority, design, the mixing of the 2 data strands in the studies, and the justifications authors provide for using mixed methods. Furthermore, the articles were evaluated in terms of how well they met contemporary definitions for mixed methods research. The studies varied considerably in the use and understanding of mixed methods. A systematic evaluation of the employment of mixed methods methodology was used to identify the studies that best reflected contemporary definitions. A comparison to earlier content analyses of mixed methods research indicates that researchers' knowledge of mixed methods methodology may be increasing. The use of this strategy in science education research calls, however, for an improved methodology, especially concerning the practice of mixing. Suggestions are given on how to best use this approach.

Structural issues affecting mixed methods studies in health research: a qualitative study.

PubMed

O'Cathain, Alicia; Nicholl, Jon; Murphy, Elizabeth

2009-12-09

Health researchers undertake studies which combine qualitative and quantitative methods. Little attention has been paid to the structural issues affecting this mixed methods approach. We explored the facilitators and barriers to undertaking mixed methods studies in health research. Face-to-face semi-structured interviews with 20 researchers experienced in mixed methods research in health in the United Kingdom. Structural facilitators for undertaking mixed methods studies included a perception that funding bodies promoted this approach, and the multidisciplinary constituency of some university departments. Structural barriers to exploiting the potential of these studies included a lack of education and training in mixed methods research, and a lack of templates for reporting mixed methods articles in peer-reviewed journals. The 'hierarchy of evidence' relating to effectiveness studies in health care research, with the randomised controlled trial as the gold standard, appeared to pervade the health research infrastructure. Thus integration of data and findings from qualitative and quantitative components of mixed methods studies, and dissemination of integrated outputs, tended to occur through serendipity and effort, further highlighting the presence of structural constraints. Researchers are agents who may also support current structures - journal reviewers and editors, and directors of postgraduate training courses - and thus have the ability to improve the structural support for exploiting the potential of mixed methods research. The environment for health research in the UK appears to be conducive to mixed methods research but not to exploiting the potential of this approach. Structural change, as well as change in researcher behaviour, will be necessary if researchers are to fully exploit the potential of using mixed methods research.

Structural issues affecting mixed methods studies in health research: a qualitative study

PubMed Central

2009-01-01

Background Health researchers undertake studies which combine qualitative and quantitative methods. Little attention has been paid to the structural issues affecting this mixed methods approach. We explored the facilitators and barriers to undertaking mixed methods studies in health research. Methods Face-to-face semi-structured interviews with 20 researchers experienced in mixed methods research in health in the United Kingdom. Results Structural facilitators for undertaking mixed methods studies included a perception that funding bodies promoted this approach, and the multidisciplinary constituency of some university departments. Structural barriers to exploiting the potential of these studies included a lack of education and training in mixed methods research, and a lack of templates for reporting mixed methods articles in peer-reviewed journals. The 'hierarchy of evidence' relating to effectiveness studies in health care research, with the randomised controlled trial as the gold standard, appeared to pervade the health research infrastructure. Thus integration of data and findings from qualitative and quantitative components of mixed methods studies, and dissemination of integrated outputs, tended to occur through serendipity and effort, further highlighting the presence of structural constraints. Researchers are agents who may also support current structures - journal reviewers and editors, and directors of postgraduate training courses - and thus have the ability to improve the structural support for exploiting the potential of mixed methods research. Conclusion The environment for health research in the UK appears to be conducive to mixed methods research but not to exploiting the potential of this approach. Structural change, as well as change in researcher behaviour, will be necessary if researchers are to fully exploit the potential of using mixed methods research. PMID:20003210

Including mixed methods research in systematic reviews: examples from qualitative syntheses in TB and malaria control.

PubMed

Atkins, Salla; Launiala, Annika; Kagaha, Alexander; Smith, Helen

2012-04-30

Health policy makers now have access to a greater number and variety of systematic reviews to inform different stages in the policy making process, including reviews of qualitative research. The inclusion of mixed methods studies in systematic reviews is increasing, but these studies pose particular challenges to methods of review. This article examines the quality of the reporting of mixed methods and qualitative-only studies. We used two completed systematic reviews to generate a sample of qualitative studies and mixed method studies in order to make an assessment of how the quality of reporting and rigor of qualitative-only studies compares with that of mixed-methods studies. Overall, the reporting of qualitative studies in our sample was consistently better when compared with the reporting of mixed methods studies. We found that mixed methods studies are less likely to provide a description of the research conduct or qualitative data analysis procedures and less likely to be judged credible or provide rich data and thick description compared with standalone qualitative studies. Our time-related analysis shows that for both types of study, papers published since 2003 are more likely to report on the study context, describe analysis procedures, and be judged credible and provide rich data. However, the reporting of other aspects of research conduct (i.e. descriptions of the research question, the sampling strategy, and data collection methods) in mixed methods studies does not appear to have improved over time. Mixed methods research makes an important contribution to health research in general, and could make a more substantial contribution to systematic reviews. Through our careful analysis of the quality of reporting of mixed methods and qualitative-only research, we have identified areas that deserve more attention in the conduct and reporting of mixed methods research.

Pragmatism, Evidence, and Mixed Methods Evaluation

ERIC Educational Resources Information Center

Hall, Jori N.

2013-01-01

Mixed methods evaluation has a long-standing history of enhancing the credibility of evaluation findings. However, using mixed methods in a utilitarian way implicitly emphasizes convenience over engaging with its philosophical underpinnings (Denscombe, 2008). Because of this, some mixed methods evaluators and social science researchers have been…

Mixed-methods research in nursing - a critical review.

PubMed

Bressan, Valentina; Bagnasco, Annamaria; Aleo, Giuseppe; Timmins, Fiona; Barisone, Michela; Bianchi, Monica; Pellegrini, Ramona; Sasso, Loredana

2017-10-01

To review the use of mixed-methods research in nursing with a particular focus on the extent to which current practice informs nurse researchers. It also aimed to highlight gaps in current knowledge, understanding and reporting of this type of research. Mixed-methods research is becoming increasingly popular among nurses and healthcare professionals. Emergent findings from this type of research are very useful for nurses in practice. The combination of both quantitative and qualitative methods provides a scientific base for practice but also richness from the qualitative enquiry. However, at the same time mixed-methods research is underdeveloped. This study identified mixed-methods research papers and critically evaluated their usefulness for research practice. To support the analysis, we performed a two-stage search using CINAHL to find papers with titles that included the key term 'mixed method'. An analysis of studies that used mixed-methods research revealed some inconsistencies in application and reporting. Attempts to use two distinct research methods in these studies often meant that one or both aspects had limitations. Overall methods were applied in a less rigorous way. This has implications for providing somewhat limited direction for novice researchers. There is also potential for application of evidence in healthcare practice that limited validity. This study highlights current gaps in knowledge, understanding and reporting of mixed-methods research. While these methods are useful to gain insight into clinical problems nurses lack guidance with this type of research. This study revealed that the guidance provided by current mixed-methods research is inconsistent and incomplete and this compounds the lack of available direction. There is an urgent need to develop robust guidelines for using mixed-methods research so that findings may be critically implemented in practice. © 2016 John Wiley & Sons Ltd.

Mixed Methods in Biomedical and Health Services Research

PubMed Central

Curry, Leslie A.; Krumholz, Harlan M.; O’Cathain, Alicia; Plano Clark, Vicki L.; Cherlin, Emily; Bradley, Elizabeth H.

2013-01-01

Mixed methods studies, in which qualitative and quantitative methods are combined in a single program of inquiry, can be valuable in biomedical and health services research, where the complementary strengths of each approach can yield greater insight into complex phenomena than either approach alone. Although interest in mixed methods is growing among science funders and investigators, written guidance on how to conduct and assess rigorous mixed methods studies is not readily accessible to the general readership of peer-reviewed biomedical and health services journals. Furthermore, existing guidelines for publishing mixed methods studies are not well known or applied by researchers and journal editors. Accordingly, this paper is intended to serve as a concise, practical resource for readers interested in core principles and practices of mixed methods research. We briefly describe mixed methods approaches and present illustrations from published biomedical and health services literature, including in cardiovascular care, summarize standards for the design and reporting of these studies, and highlight four central considerations for investigators interested in using these methods. PMID:23322807

Trends in the Contraceptive Method Mix in Low- and Middle-Income Countries: Analysis Using a New “Average Deviation” Measure

PubMed Central

Ross, John; Keesbury, Jill; Hardee, Karen

2015-01-01

ABSTRACT The method mix of contraceptive use is severely unbalanced in many countries, with over half of all use provided by just 1 or 2 methods. That tends to limit the range of user options and constrains the total prevalence of use, leading to unplanned pregnancies and births or abortions. Previous analyses of method mix distortions focused on countries where a single method accounted for more than half of all use (the 50% rule). We introduce a new measure that uses the average deviation (AD) of method shares around their own mean and apply that to a secondary analysis of method mix data for 8 contraceptive methods from 666 national surveys in 123 countries. A high AD value indicates a skewed method mix while a low AD value indicates a more uniform pattern across methods; the values can range from 0 to 21.9. Most AD values ranged from 6 to 19, with an interquartile range of 8.6 to 12.2. Using the AD measure, we identified 15 countries where the method mix has evolved from a distorted one to a better balanced one, with AD values declining, on average, by 35% over time. Countries show disparate paths in method gains and losses toward a balanced mix, but 4 patterns are suggested: (1) rise of one method partially offset by changes in other methods, (2) replacement of traditional with modern methods, (3) continued but declining domination by a single method, and (4) declines in dominant methods with increases in other methods toward a balanced mix. Regions differ markedly in their method mix profiles and preferences, raising the question of whether programmatic resources are best devoted to better provision of the well-accepted methods or to deploying neglected or new ones, or to a combination of both approaches. PMID:25745119

Using mixed methods to develop and evaluate complex interventions in palliative care research.

PubMed

Farquhar, Morag C; Ewing, Gail; Booth, Sara

2011-12-01

there is increasing interest in combining qualitative and quantitative research methods to provide comprehensiveness and greater knowledge yield. Mixed methods are valuable in the development and evaluation of complex interventions. They are therefore particularly valuable in palliative care research where the majority of interventions are complex, and the identification of outcomes particularly challenging. this paper aims to introduce the role of mixed methods in the development and evaluation of complex interventions in palliative care, and how they may be used in palliative care research. the paper defines mixed methods and outlines why and how mixed methods are used to develop and evaluate complex interventions, with a pragmatic focus on design and data collection issues and data analysis. Useful texts are signposted and illustrative examples provided of mixed method studies in palliative care, including a detailed worked example of the development and evaluation of a complex intervention in palliative care for breathlessness. Key challenges to conducting mixed methods in palliative care research are identified in relation to data collection, data integration in analysis, costs and dissemination and how these might be addressed. the development and evaluation of complex interventions in palliative care benefit from the application of mixed methods. Mixed methods enable better understanding of whether and how an intervention works (or does not work) and inform the design of subsequent studies. However, they can be challenging: mixed method studies in palliative care will benefit from working with agreed protocols, multidisciplinary teams and engaging staff with appropriate skill sets.

Breaking from binaries - using a sequential mixed methods design.

PubMed

Larkin, Patricia Mary; Begley, Cecily Marion; Devane, Declan

2014-03-01

To outline the traditional worldviews of healthcare research and discuss the benefits and challenges of using mixed methods approaches in contributing to the development of nursing and midwifery knowledge. There has been much debate about the contribution of mixed methods research to nursing and midwifery knowledge in recent years. A sequential exploratory design is used as an exemplar of a mixed methods approach. The study discussed used a combination of focus-group interviews and a quantitative instrument to obtain a fuller understanding of women's experiences of childbirth. In the mixed methods study example, qualitative data were analysed using thematic analysis and quantitative data using regression analysis. Polarised debates about the veracity, philosophical integrity and motivation for conducting mixed methods research have largely abated. A mixed methods approach can contribute to a deeper, more contextual understanding of a variety of subjects and experiences; as a result, it furthers knowledge that can be used in clinical practice. The purpose of the research study should be the main instigator when choosing from an array of mixed methods research designs. Mixed methods research offers a variety of models that can augment investigative capabilities and provide richer data than can a discrete method alone. This paper offers an example of an exploratory, sequential approach to investigating women's childbirth experiences. A clear framework for the conduct and integration of the different phases of the mixed methods research process is provided. This approach can be used by practitioners and policy makers to improve practice.

Development of a Self-Rated Mixed Methods Skills Assessment: The National Institutes of Health Mixed Methods Research Training Program for the Health Sciences.

PubMed

Guetterman, Timothy C; Creswell, John W; Wittink, Marsha; Barg, Fran K; Castro, Felipe G; Dahlberg, Britt; Watkins, Daphne C; Deutsch, Charles; Gallo, Joseph J

2017-01-01

Demand for training in mixed methods is high, with little research on faculty development or assessment in mixed methods. We describe the development of a self-rated mixed methods skills assessment and provide validity evidence. The instrument taps six research domains: "Research question," "Design/approach," "Sampling," "Data collection," "Analysis," and "Dissemination." Respondents are asked to rate their ability to define or explain concepts of mixed methods under each domain, their ability to apply the concepts to problems, and the extent to which they need to improve. We administered the questionnaire to 145 faculty and students using an internet survey. We analyzed descriptive statistics and performance characteristics of the questionnaire using the Cronbach alpha to assess reliability and an analysis of variance that compared a mixed methods experience index with assessment scores to assess criterion relatedness. Internal consistency reliability was high for the total set of items (0.95) and adequate (≥0.71) for all but one subscale. Consistent with establishing criterion validity, respondents who had more professional experiences with mixed methods (eg, published a mixed methods article) rated themselves as more skilled, which was statistically significant across the research domains. This self-rated mixed methods assessment instrument may be a useful tool to assess skills in mixed methods for training programs. It can be applied widely at the graduate and faculty level. For the learner, assessment may lead to enhanced motivation to learn and training focused on self-identified needs. For faculty, the assessment may improve curriculum and course content planning.

Development of a Self-Rated Mixed Methods Skills Assessment: The NIH Mixed Methods Research Training Program for the Health Sciences

PubMed Central

Guetterman, Timothy C.; Creswell, John W.; Wittink, Marsha; Barg, Fran K.; Castro, Felipe G.; Dahlberg, Britt; Watkins, Daphne C.; Deutsch, Charles; Gallo, Joseph J.

2017-01-01

Introduction Demand for training in mixed methods is high, with little research on faculty development or assessment in mixed methods. We describe the development of a Self-Rated Mixed Methods Skills Assessment and provide validity evidence. The instrument taps six research domains: “Research question,” “Design/approach,” “Sampling,” “Data collection,” “Analysis,” and “Dissemination.” Respondents are asked to rate their ability to define or explain concepts of mixed methods under each domain, their ability to apply the concepts to problems, and the extent to which they need to improve. Methods We administered the questionnaire to 145 faculty and students using an internet survey. We analyzed descriptive statistics and performance characteristics of the questionnaire using Cronbach’s alpha to assess reliability and an ANOVA that compared a mixed methods experience index with assessment scores to assess criterion-relatedness. Results Internal consistency reliability was high for the total set of items (.95) and adequate (>=.71) for all but one subscale. Consistent with establishing criterion validity, respondents who had more professional experiences with mixed methods (e.g., published a mixed methods paper) rated themselves as more skilled, which was statistically significant across the research domains. Discussion This Self-Rated Mixed Methods Assessment instrument may be a useful tool to assess skills in mixed methods for training programs. It can be applied widely at the graduate and faculty level. For the learner, assessment may lead to enhanced motivation to learn and training focused on self-identified needs. For faculty, the assessment may improve curriculum and course content planning. PMID:28562495

Mixed Methods in Emerging Academic Subdisciplines: The Case of Sport Management

ERIC Educational Resources Information Center

van der Roest, Jan-Willem; Spaaij, Ramón; van Bottenburg, Maarten

2015-01-01

This article examines the prevalence and characteristics of mixed methods research in the relatively new subdiscipline of sport management. A mixed methods study is undertaken to evaluate the epistemological/philosophical, methodological, and technical levels of mixed methods design in sport management research. The results indicate that mixed…

Qualitative Approaches to Mixed Methods Practice

ERIC Educational Resources Information Center

Hesse-Biber, Sharlene

2010-01-01

This article discusses how methodological practices can shape and limit how mixed methods is practiced and makes visible the current methodological assumptions embedded in mixed methods practice that can shut down a range of social inquiry. The article argues that there is a "methodological orthodoxy" in how mixed methods is practiced…

Educational Accountability: A Qualitatively Driven Mixed-Methods Approach

ERIC Educational Resources Information Center

Hall, Jori N.; Ryan, Katherine E.

2011-01-01

This article discusses the importance of mixed-methods research, in particular the value of qualitatively driven mixed-methods research for quantitatively driven domains like educational accountability. The article demonstrates the merits of qualitative thinking by describing a mixed-methods study that focuses on a middle school's system of…

Including mixed methods research in systematic reviews: Examples from qualitative syntheses in TB and malaria control

PubMed Central

2012-01-01

Background Health policy makers now have access to a greater number and variety of systematic reviews to inform different stages in the policy making process, including reviews of qualitative research. The inclusion of mixed methods studies in systematic reviews is increasing, but these studies pose particular challenges to methods of review. This article examines the quality of the reporting of mixed methods and qualitative-only studies. Methods We used two completed systematic reviews to generate a sample of qualitative studies and mixed method studies in order to make an assessment of how the quality of reporting and rigor of qualitative-only studies compares with that of mixed-methods studies. Results Overall, the reporting of qualitative studies in our sample was consistently better when compared with the reporting of mixed methods studies. We found that mixed methods studies are less likely to provide a description of the research conduct or qualitative data analysis procedures and less likely to be judged credible or provide rich data and thick description compared with standalone qualitative studies. Our time-related analysis shows that for both types of study, papers published since 2003 are more likely to report on the study context, describe analysis procedures, and be judged credible and provide rich data. However, the reporting of other aspects of research conduct (i.e. descriptions of the research question, the sampling strategy, and data collection methods) in mixed methods studies does not appear to have improved over time. Conclusions Mixed methods research makes an important contribution to health research in general, and could make a more substantial contribution to systematic reviews. Through our careful analysis of the quality of reporting of mixed methods and qualitative-only research, we have identified areas that deserve more attention in the conduct and reporting of mixed methods research. PMID:22545681

Mixed Methods, Triangulation, and Causal Explanation

ERIC Educational Resources Information Center

Howe, Kenneth R.

2012-01-01

This article distinguishes a disjunctive conception of mixed methods/triangulation, which brings different methods to bear on different questions, from a conjunctive conception, which brings different methods to bear on the same question. It then examines a more inclusive, holistic conception of mixed methods/triangulation that accommodates…

Mixing it but not mixed-up: mixed methods research in medical education (a critical narrative review).

PubMed

Maudsley, Gillian

2011-01-01

Some important research questions in medical education and health services research need 'mixed methods research' (particularly synthesizing quantitative and qualitative findings). The approach is not new, but should be more explicitly reported. The broad search question here, of a disjointed literature, was thus: What is mixed methods research - how should it relate to medical education research?, focused on explicit acknowledgement of 'mixing'. Literature searching focused on Web of Knowledge supplemented by other databases across disciplines. Five main messages emerged: - Thinking quantitative and qualitative, not quantitative versus qualitative - Appreciating that mixed methods research blends different knowledge claims, enquiry strategies, and methods - Using a 'horses for courses' [whatever works] approach to the question, and clarifying the mix - Appreciating how medical education research competes with the 'evidence-based' movement, health services research, and the 'RCT' - Being more explicit about the role of mixed methods in medical education research, and the required expertise Mixed methods research is valuable, yet the literature relevant to medical education is fragmented and poorly indexed. The required time, effort, expertise, and techniques deserve better recognition. More write-ups should explicitly discuss the 'mixing' (particularly of findings), rather than report separate components.

Student Characteristics, Prior Experiences, and the Perception of Mixed Methods as an Innovation

ERIC Educational Resources Information Center

Brown, Sydney E.

2014-01-01

There are persistent challenges to teaching mixed methods and innovative solutions are sought in order to address the needs of an increasingly diverse global audience seeking mixed methods instruction. This mixed methods study was conducted to gain insights to course design by more fully understanding the relationships among graduate student…

Validity in Mixed Methods Research in Education: The Application of Habermas' Critical Theory

ERIC Educational Resources Information Center

Long, Haiying

2017-01-01

Mixed methods approach has developed into the third methodological movement in educational research. Validity in mixed methods research as an important issue, however, has not been examined as extensively as that of quantitative and qualitative research. Additionally, the previous discussions of validity in mixed methods research focus on research…

Moments, Mixed Methods, and Paradigm Dialogs

ERIC Educational Resources Information Center

Denzin, Norman K.

2010-01-01

I reread the 50-year-old history of the qualitative inquiry that calls for triangulation and mixed methods. I briefly visit the disputes within the mixed methods community asking how did we get to where we are today, the period of mixed-multiple-methods advocacy, and Teddlie and Tashakkori's third methodological moment. (Contains 10 notes.)

Integrative Mixed Methods Data Analytic Strategies in Research on School Success in Challenging Circumstances

ERIC Educational Resources Information Center

Jang, Eunice E.; McDougall, Douglas E.; Pollon, Dawn; Herbert, Monique; Russell, Pia

2008-01-01

There are both conceptual and practical challenges in dealing with data from mixed methods research studies. There is a need for discussion about various integrative strategies for mixed methods data analyses. This article illustrates integrative analytic strategies for a mixed methods study focusing on improving urban schools facing challenging…

The Structure of Mixed Method Studies in Educational Research: A Content Analysis

ERIC Educational Resources Information Center

Bryant, Lauren H.

2011-01-01

Educational researchers are beginning to use mixed methods designs to answer complex research questions. This content analysis investigates the structure and use of mixed methods in educational research in order to work toward a more standardized presentation. I used a concurrent mixed methods approach to analyze 30 studies from three prominent…

Realism and Pragmatism in a mixed methods study.

PubMed

Allmark, Peter; Machaczek, Katarzyna

2018-06-01

A discussion of how adopting a Realist rather than Pragmatist methodology affects the conduct of mixed methods research. Mixed methods approaches are now extensively employed in nursing and other healthcare research. At the same time, realist methodology is increasingly used as philosophical underpinning of research in these areas. However, the standard philosophical underpinning of mixed methods research is Pragmatism, which is generally considered incompatible or at least at odds with Realism. This paper argues that Realism can be used as the basis of mixed methods research and that doing so carries advantages over using Pragmatism. A mixed method study into patient handover reports is used to illustrate how Realism affected its design and how it would have differed had a Pragmatist approach been taken. Discussion Paper. Philosophers Index; Google Scholar. Those undertaking mixed methods research should consider the use of Realist methodology with the addition of some insights from Pragmatism to do with the start and end points of enquiry. Realism is a plausible alternative methodology for those undertaking mixed methods studies. © 2018 John Wiley & Sons Ltd.

Mixed-methods designs in mental health services research: a review.

PubMed

Palinkas, Lawrence A; Horwitz, Sarah M; Chamberlain, Patricia; Hurlburt, Michael S; Landsverk, John

2011-03-01

Despite increased calls for use of mixed-methods designs in mental health services research, how and why such methods are being used and whether there are any consistent patterns that might indicate a consensus about how such methods can and should be used are unclear. Use of mixed methods was examined in 50 peer-reviewed journal articles found by searching PubMed Central and 60 National Institutes of Health (NIH)-funded projects found by searching the CRISP database over five years (2005-2009). Studies were coded for aims and the rationale, structure, function, and process for using mixed methods. A notable increase was observed in articles published and grants funded over the study period. However, most did not provide an explicit rationale for using mixed methods, and 74% gave priority to use of quantitative methods. Mixed methods were used to accomplish five distinct types of study aims (assess needs for services, examine existing services, develop new or adapt existing services, evaluate services in randomized controlled trials, and examine service implementation), with three categories of rationale, seven structural arrangements based on timing and weighting of methods, five functions of mixed methods, and three ways of linking quantitative and qualitative data. Each study aim was associated with a specific pattern of use of mixed methods, and four common patterns were identified. These studies offer guidance for continued progress in integrating qualitative and quantitative methods in mental health services research consistent with efforts by NIH and other funding agencies to promote their use.

Using mixed methods in health research

PubMed Central

Woodman, Jenny

2013-01-01

Summary Mixed methods research is the use of quantitative and qualitative methods in a single study or series of studies. It is an emergent methodology which is increasingly used by health researchers, especially within health services research. There is a growing literature on the theory, design and critical appraisal of mixed methods research. However, there are few papers that summarize this methodological approach for health practitioners who wish to conduct or critically engage with mixed methods studies. The objective of this paper is to provide an accessible introduction to mixed methods for clinicians and researchers unfamiliar with this approach. We present a synthesis of key methodological literature on mixed methods research, with examples from our own work and that of others, to illustrate the practical applications of this approach within health research. We summarize definitions of mixed methods research, the value of this approach, key aspects of study design and analysis, and discuss the potential challenges of combining quantitative and qualitative methods and data. One of the key challenges within mixed methods research is the successful integration of quantitative and qualitative data during analysis and interpretation. However, the integration of different types of data can generate insights into a research question, resulting in enriched understanding of complex health research problems. PMID:23885291

Methodological reporting in qualitative, quantitative, and mixed methods health services research articles.

PubMed

Wisdom, Jennifer P; Cavaleri, Mary A; Onwuegbuzie, Anthony J; Green, Carla A

2012-04-01

Methodologically sound mixed methods research can improve our understanding of health services by providing a more comprehensive picture of health services than either method can alone. This study describes the frequency of mixed methods in published health services research and compares the presence of methodological components indicative of rigorous approaches across mixed methods, qualitative, and quantitative articles. All empirical articles (n = 1,651) published between 2003 and 2007 from four top-ranked health services journals. All mixed methods articles (n = 47) and random samples of qualitative and quantitative articles were evaluated to identify reporting of key components indicating rigor for each method, based on accepted standards for evaluating the quality of research reports (e.g., use of p-values in quantitative reports, description of context in qualitative reports, and integration in mixed method reports). We used chi-square tests to evaluate differences between article types for each component. Mixed methods articles comprised 2.85 percent (n = 47) of empirical articles, quantitative articles 90.98 percent (n = 1,502), and qualitative articles 6.18 percent (n = 102). There was a statistically significant difference (χ(2) (1) = 12.20, p = .0005, Cramer's V = 0.09, odds ratio = 1.49 [95% confidence interval = 1,27, 1.74]) in the proportion of quantitative methodological components present in mixed methods compared to quantitative papers (21.94 versus 47.07 percent, respectively) but no statistically significant difference (χ(2) (1) = 0.02, p = .89, Cramer's V = 0.01) in the proportion of qualitative methodological components in mixed methods compared to qualitative papers (21.34 versus 25.47 percent, respectively). Few published health services research articles use mixed methods. The frequency of key methodological components is variable. Suggestions are provided to increase the transparency of mixed methods studies and the presence of key methodological components in published reports. © Health Research and Educational Trust.

Methodological Reporting in Qualitative, Quantitative, and Mixed Methods Health Services Research Articles

PubMed Central

Wisdom, Jennifer P; Cavaleri, Mary A; Onwuegbuzie, Anthony J; Green, Carla A

2012-01-01

Objectives Methodologically sound mixed methods research can improve our understanding of health services by providing a more comprehensive picture of health services than either method can alone. This study describes the frequency of mixed methods in published health services research and compares the presence of methodological components indicative of rigorous approaches across mixed methods, qualitative, and quantitative articles. Data Sources All empirical articles (n = 1,651) published between 2003 and 2007 from four top-ranked health services journals. Study Design All mixed methods articles (n = 47) and random samples of qualitative and quantitative articles were evaluated to identify reporting of key components indicating rigor for each method, based on accepted standards for evaluating the quality of research reports (e.g., use of p-values in quantitative reports, description of context in qualitative reports, and integration in mixed method reports). We used chi-square tests to evaluate differences between article types for each component. Principal Findings Mixed methods articles comprised 2.85 percent (n = 47) of empirical articles, quantitative articles 90.98 percent (n = 1,502), and qualitative articles 6.18 percent (n = 102). There was a statistically significant difference (χ2(1) = 12.20, p = .0005, Cramer's V = 0.09, odds ratio = 1.49 [95% confidence interval = 1,27, 1.74]) in the proportion of quantitative methodological components present in mixed methods compared to quantitative papers (21.94 versus 47.07 percent, respectively) but no statistically significant difference (χ2(1) = 0.02, p = .89, Cramer's V = 0.01) in the proportion of qualitative methodological components in mixed methods compared to qualitative papers (21.34 versus 25.47 percent, respectively). Conclusion Few published health services research articles use mixed methods. The frequency of key methodological components is variable. Suggestions are provided to increase the transparency of mixed methods studies and the presence of key methodological components in published reports. PMID:22092040

Mixed methods research.

PubMed

Halcomb, Elizabeth; Hickman, Louise

2015-04-08

Mixed methods research involves the use of qualitative and quantitative data in a single research project. It represents an alternative methodological approach, combining qualitative and quantitative research approaches, which enables nurse researchers to explore complex phenomena in detail. This article provides a practical overview of mixed methods research and its application in nursing, to guide the novice researcher considering a mixed methods research project.

A Case Study of a Mixed Methods Study Engaged in Integrated Data Analysis

ERIC Educational Resources Information Center

Schiazza, Daniela Marie

2013-01-01

The nascent field of mixed methods research has yet to develop a cohesive framework of guidelines and procedures for mixed methods data analysis (Greene, 2008). To support the field's development of analytical frameworks, this case study reflects on the development and implementation of a mixed methods study engaged in integrated data analysis.…

The use of "mixing" procedure of mixed methods in health services research.

PubMed

Zhang, Wanqing; Creswell, John

2013-08-01

Mixed methods research has emerged alongside qualitative and quantitative approaches as an important tool for health services researchers. Despite growing interest, among health services researchers, in using mixed methods designs, little has been done to identify the procedural aspects of doing so. To describe how mixed methods researchers mix the qualitative and quantitative aspects of their studies in health services research. We searched the PubMed for articles, using mixed methods in health services research, published between January 1, 2006 and December 30, 2010. We identified and reviewed 30 published health services research articles on studies in which mixed methods had been used. We selected 3 articles as illustrations to help health services researcher conceptualize the type of mixing procedures that they were using. Three main "mixing" procedures have been applied within these studies: (1) the researchers analyzed the 2 types of data at the same time but separately and integrated the results during interpretation; (2) the researchers connected the qualitative and quantitative portions in phases in such a way that 1 approach was built upon the findings of the other approach; and (3) the researchers mixed the 2 data types by embedding the analysis of 1 data type within the other. "Mixing" in mixed methods is more than just the combination of 2 independent components of the quantitative and qualitative data. The use of "mixing" procedure in health services research involves the integration, connection, and embedding of these 2 data components.

Writing a Mixed Methods Report in Social Work Research

ERIC Educational Resources Information Center

Bronstein, Laura R.; Kovacs, Pamela J.

2013-01-01

This article briefly chronicles the development of mixed methods research and its use in social work. We then move onto a discussion of terms and designs, reasons for (and for not) using mixed methods. Drawing upon exemplars, we address how to write up a mixed methods study when (1) the sample is single; single for one part, with a subset for the…

A Preliminary Rubric Design to Evaluate Mixed Methods Research

ERIC Educational Resources Information Center

Burrows, Timothy J.

2013-01-01

With the increase in frequency of the use of mixed methods, both in research publications and in externally funded grants there are increasing calls for a set of standards to assess the quality of mixed methods research. The purpose of this mixed methods study was to conduct a multi-phase analysis to create a preliminary rubric to evaluate mixed…

10 best resources on ... mixed methods research in health systems.

PubMed

Ozawa, Sachiko; Pongpirul, Krit

2014-05-01

Mixed methods research has become increasingly popular in health systems. Qualitative approaches are often used to explain quantitative results and help to develop interventions or survey instruments. Mixed methods research is especially important in low- and middle-income country (LMIC) settings, where understanding social, economic and cultural contexts are essential to assess health systems performance. To provide researchers and programme managers with a guide to mixed methods research in health systems, we review the best resources with a focus on LMICs. We selected 10 best resources (eight peer-reviewed articles and two textbooks) based on their importance and frequency of use (number of citations), comprehensiveness of content, usefulness to readers and relevance to health systems research in resource-limited contexts. We start with an overview on mixed methods research and discuss resources that are useful for a better understanding of the design and conduct of mixed methods research. To illustrate its practical applications, we provide examples from various countries (China, Vietnam, Kenya, Tanzania, Zambia and India) across different health topics (tuberculosis, malaria, HIV testing and healthcare costs). We conclude with some toolkits which suggest what to do when mixed methods findings conflict and provide guidelines for evaluating the quality of mixed methods research.

Mixed-methods research in pharmacy practice: basics and beyond (part 1).

PubMed

Hadi, Muhammad Abdul; Alldred, David Phillip; Closs, S José; Briggs, Michelle

2013-10-01

This is the first of two papers which explore the use of mixed-methods research in pharmacy practice. In an era of evidence-based medicine and policy, high-quality research evidence is essential for the development of effective pharmacist-led services. Over the past decade, the use of mixed-methods research has become increasingly common in healthcare, although to date its use has been relatively limited in pharmacy practice research. In this article, the basic concepts of mixed-methods research including its definition, typologies and advantages in relation to pharmacy practice research are discussed. Mixed-methods research brings together qualitative and quantitative methodologies within a single study to answer or understand a research problem. There are a number of mixed-methods designs available, but the selection of an appropriate design must always be dictated by the research question. Importantly, mixed-methods research should not be seen as a 'tool' to collect qualitative and quantitative data, rather there should be some degree of 'integration' between the two data sets. If conducted appropriately, mixed-methods research has the potential to generate quality research evidence by combining strengths and overcoming the respective limitations of qualitative and quantitative methodologies. © 2012 Royal Pharmaceutical Society.

A brief measure of attitudes toward mixed methods research in psychology.

PubMed

Roberts, Lynne D; Povee, Kate

2014-01-01

The adoption of mixed methods research in psychology has trailed behind other social science disciplines. Teaching psychology students, academics, and practitioners about mixed methodologies may increase the use of mixed methods within the discipline. However, tailoring and evaluating education and training in mixed methodologies requires an understanding of, and way of measuring, attitudes toward mixed methods research in psychology. To date, no such measure exists. In this article we present the development and initial validation of a new measure: Attitudes toward Mixed Methods Research in Psychology. A pool of 42 items developed from previous qualitative research on attitudes toward mixed methods research along with validation measures was administered via an online survey to a convenience sample of 274 psychology students, academics and psychologists. Principal axis factoring with varimax rotation on a subset of the sample produced a four-factor, 12-item solution. Confirmatory factor analysis on a separate subset of the sample indicated that a higher order four factor model provided the best fit to the data. The four factors; 'Limited Exposure,' '(in)Compatibility,' 'Validity,' and 'Tokenistic Qualitative Component'; each have acceptable internal reliability. Known groups validity analyses based on preferred research orientation and self-rated mixed methods research skills, and convergent and divergent validity analyses based on measures of attitudes toward psychology as a science and scientist and practitioner orientation, provide initial validation of the measure. This brief, internally reliable measure can be used in assessing attitudes toward mixed methods research in psychology, measuring change in attitudes as part of the evaluation of mixed methods education, and in larger research programs.

Criteria for quantitative and qualitative data integration: mixed-methods research methodology.

PubMed

Lee, Seonah; Smith, Carrol A M

2012-05-01

Many studies have emphasized the need and importance of a mixed-methods approach for evaluation of clinical information systems. However, those studies had no criteria to guide integration of multiple data sets. Integrating different data sets serves to actualize the paradigm that a mixed-methods approach argues; thus, we require criteria that provide the right direction to integrate quantitative and qualitative data. The first author used a set of criteria organized from a literature search for integration of multiple data sets from mixed-methods research. The purpose of this article was to reorganize the identified criteria. Through critical appraisal of the reasons for designing mixed-methods research, three criteria resulted: validation, complementarity, and discrepancy. In applying the criteria to empirical data of a previous mixed methods study, integration of quantitative and qualitative data was achieved in a systematic manner. It helped us obtain a better organized understanding of the results. The criteria of this article offer the potential to produce insightful analyses of mixed-methods evaluations of health information systems.

The influence of different black carbon and sulfate mixing methods on their optical and radiative properties

NASA Astrophysics Data System (ADS)

Zhang, Hua; Zhou, Chen; Wang, Zhili; Zhao, Shuyun; Li, Jiangnan

2015-08-01

Three different internal mixing methods (Core-Shell, Maxwell-Garnett, and Bruggeman) and one external mixing method are used to study the impact of mixing methods of black carbon (BC) with sulfate aerosol on their optical properties, radiative flux, and heating rate. The optical properties of a mixture of BC and sulfate aerosol particles are considered for three typical bands. The results show that mixing methods, the volume ratio of BC to sulfate, and relative humidity have a strong influence on the optical properties of mixed aerosols. Compared to internal mixing, external mixing underestimates the particle mass absorption coefficient by 20-70% and the particle mass scattering coefficient by up to 50%, whereas it overestimates the particle single scattering albedo by 20-50% in most cases. However, the asymmetry parameter is strongly sensitive to the equivalent particle radius, but is only weakly sensitive to the different mixing methods. Of the internal methods, there is less than 2% difference in all optical properties between the Maxwell-Garnett and Bruggeman methods in all bands; however, the differences between the Core-Shell and Maxwell-Garnett/Bruggeman methods are usually larger than 15% in the ultraviolet and visible bands. A sensitivity test is conducted with the Beijing Climate Center Radiation transfer model (BCC-RAD) using a simulated BC concentration that is typical of east-central China and a sulfate volume ratio of 75%. The results show that the internal mixing methods could reduce the radiative flux more effectively because they produce a higher absorption. The annual mean instantaneous radiative force due to BC-sulfate aerosol is about -3.18 W/m2 for the external method and -6.91 W/m2 for the internal methods at the surface, and -3.03/-1.56/-1.85 W/m2 for the external/Core-Shell/(Maxwell-Garnett/Bruggeman) methods, respectively, at the tropopause.

Dynamic reflexivity in action: an armchair walkthrough of a qualitatively driven mixed-method and multiple methods study of mindfulness training in schoolchildren.

PubMed

Cheek, Julianne; Lipschitz, David L; Abrams, Elizabeth M; Vago, David R; Nakamura, Yoshio

2015-06-01

Dynamic reflexivity is central to enabling flexible and emergent qualitatively driven inductive mixed-method and multiple methods research designs. Yet too often, such reflexivity, and how it is used at various points of a study, is absent when we write our research reports. Instead, reports of mixed-method and multiple methods research focus on what was done rather than how it came to be done. This article seeks to redress this absence of emphasis on the reflexive thinking underpinning the way that mixed- and multiple methods, qualitatively driven research approaches are thought about and subsequently used throughout a project. Using Morse's notion of an armchair walkthrough, we excavate and explore the layers of decisions we made about how, and why, to use qualitatively driven mixed-method and multiple methods research in a study of mindfulness training (MT) in schoolchildren. © The Author(s) 2015.

Mixed methods for telehealth research.

PubMed

Caffery, Liam J; Martin-Khan, Melinda; Wade, Victoria

2017-10-01

Mixed methods research is important to health services research because the integrated qualitative and quantitative investigation can give a more comprehensive understanding of complex interventions such as telehealth than can a single-method study. Further, mixed methods research is applicable to translational research and program evaluation. Study designs relevant to telehealth research are described and supported by examples. Quality assessment tools, frameworks to assist in the reporting and review of mixed methods research, and related methodologies are also discussed.

[Mixed methods research in public health: issues and illustration].

PubMed

Guével, Marie-Renée; Pommier, Jeanine

2012-01-01

For many years, researchers in a range of fields have combined quantitative and qualitative methods. However, the combined use of quantitative and qualitative methods has only recently been conceptualized and defined as mixed methods research. Some authors have described the emerging field as a third methodological tradition (in addition to the qualitative and quantitative traditions). Mixed methods research combines different perspectives and facilitates the study of complex interventions or programs, particularly in public health, an area where interdisciplinarity is critical. However, the existing literature is primarily in English. By contrast, the literature in French remains limited. The purpose of this paper is to present the emergence of mixed methods research for francophone public health specialists. A literature review was conducted to identify the main characteristics of mixed methods research. The results provide an overall picture of the mixed methods approach through its history, definitions, and applications, and highlight the tools developed to clarify the approach (typologies) and to implement it (integration of results and quality standards). The tools highlighted in the literature review are illustrated by a study conducted in France. Mixed methods research opens new possibilities for examining complex research questions and provides relevant and promising opportunities for addressing current public health issues in France.

Text-in-context: a method for extracting findings in mixed-methods mixed research synthesis studies.

PubMed

Sandelowski, Margarete; Leeman, Jennifer; Knafl, Kathleen; Crandell, Jamie L

2013-06-01

Our purpose in this paper is to propose a new method for extracting findings from research reports included in mixed-methods mixed research synthesis studies. International initiatives in the domains of systematic review and evidence synthesis have been focused on broadening the conceptualization of evidence, increased methodological inclusiveness and the production of evidence syntheses that will be accessible to and usable by a wider range of consumers. Initiatives in the general mixed-methods research field have been focused on developing truly integrative approaches to data analysis and interpretation. The data extraction challenges described here were encountered, and the method proposed for addressing these challenges was developed, in the first year of the ongoing (2011-2016) study: Mixed-Methods Synthesis of Research on Childhood Chronic Conditions and Family. To preserve the text-in-context of findings in research reports, we describe a method whereby findings are transformed into portable statements that anchor results to relevant information about sample, source of information, time, comparative reference point, magnitude and significance and study-specific conceptions of phenomena. The data extraction method featured here was developed specifically to accommodate mixed-methods mixed research synthesis studies conducted in nursing and other health sciences, but reviewers might find it useful in other kinds of research synthesis studies. This data extraction method itself constitutes a type of integration to preserve the methodological context of findings when statements are read individually and in comparison to each other. © 2012 Blackwell Publishing Ltd.

A Strategy to Identify Critical Appraisal Criteria for Primary Mixed-Method Studies

PubMed Central

Sale, Joanna E. M.; Brazil, Kevin

2015-01-01

The practice of mixed-methods research has increased considerably over the last 10 years. While these studies have been criticized for violating quantitative and qualitative paradigmatic assumptions, the methodological quality of mixed-method studies has not been addressed. The purpose of this paper is to identify criteria to critically appraise the quality of mixed-method studies in the health literature. Criteria for critically appraising quantitative and qualitative studies were generated from a review of the literature. These criteria were organized according to a cross-paradigm framework. We recommend that these criteria be applied to a sample of mixed-method studies which are judged to be exemplary. With the consultation of critical appraisal experts and experienced qualitative, quantitative, and mixed-method researchers, further efforts are required to revise and prioritize the criteria according to importance. PMID:26526412

A brief measure of attitudes toward mixed methods research in psychology

PubMed Central

Roberts, Lynne D.; Povee, Kate

2014-01-01

The adoption of mixed methods research in psychology has trailed behind other social science disciplines. Teaching psychology students, academics, and practitioners about mixed methodologies may increase the use of mixed methods within the discipline. However, tailoring and evaluating education and training in mixed methodologies requires an understanding of, and way of measuring, attitudes toward mixed methods research in psychology. To date, no such measure exists. In this article we present the development and initial validation of a new measure: Attitudes toward Mixed Methods Research in Psychology. A pool of 42 items developed from previous qualitative research on attitudes toward mixed methods research along with validation measures was administered via an online survey to a convenience sample of 274 psychology students, academics and psychologists. Principal axis factoring with varimax rotation on a subset of the sample produced a four-factor, 12-item solution. Confirmatory factor analysis on a separate subset of the sample indicated that a higher order four factor model provided the best fit to the data. The four factors; ‘Limited Exposure,’ ‘(in)Compatibility,’ ‘Validity,’ and ‘Tokenistic Qualitative Component’; each have acceptable internal reliability. Known groups validity analyses based on preferred research orientation and self-rated mixed methods research skills, and convergent and divergent validity analyses based on measures of attitudes toward psychology as a science and scientist and practitioner orientation, provide initial validation of the measure. This brief, internally reliable measure can be used in assessing attitudes toward mixed methods research in psychology, measuring change in attitudes as part of the evaluation of mixed methods education, and in larger research programs. PMID:25429281

The Influence of Elective Surgery on Functional Health in Veterans with PTSD

DTIC Science & Technology

2012-12-21

elective surgery in veterans with PTSD. Design : A longitudinal, mixed method, quasi-experimental, nonequivalent control group study was conducted...longitudinal, mixed method, quasi-experimental, nonequivalent control group study was conducted. Methods and Sample: Physical and mental health...Methods Procedures." In Research design : qualitative, quantitative , and mixed methods approaches, 203-226. Thousand Oaks, Calif.: Sage Publications

Single-Case Designs and Qualitative Methods: Applying a Mixed Methods Research Perspective

ERIC Educational Resources Information Center

Hitchcock, John H.; Nastasi, Bonnie K.; Summerville, Meredith

2010-01-01

The purpose of this conceptual paper is to describe a design that mixes single-case (sometimes referred to as single-subject) and qualitative methods, hereafter referred to as a single-case mixed methods design (SCD-MM). Minimal attention has been given to the topic of applying qualitative methods to SCD work in the literature. These two…

Mixed-Methods Design in Biology Education Research: Approach and Uses

PubMed Central

Warfa, Abdi-Rizak M.

2016-01-01

Educational research often requires mixing different research methodologies to strengthen findings, better contextualize or explain results, or minimize the weaknesses of a single method. This article provides practical guidelines on how to conduct such research in biology education, with a focus on mixed-methods research (MMR) that uses both quantitative and qualitative inquiries. Specifically, the paper provides an overview of mixed-methods design typologies most relevant in biology education research. It also discusses common methodological issues that may arise in mixed-methods studies and ways to address them. The paper concludes with recommendations on how to report and write about MMR. PMID:27856556

The Value of Developing a Mixed-Methods Program of Research.

PubMed

Simonovich, Shannon

2017-07-01

This article contributes to the discussion of the value of utilizing mixed methodological approaches to conduct nursing research. To this end, the author of this article proposes creating a mixed-methods program of research over time, where both quantitative and qualitative data are collected and analyzed simultaneously, rather than focusing efforts on designing singular mixed-methods studies. A mixed-methods program of research would allow for the best of both worlds: precision through focus on one method at a time, and the benefits of creating a robust understanding of a phenomenon over the trajectory of one's career through examination from various methodological approaches.

Applications of mixed-methods methodology in clinical pharmacy research.

PubMed

Hadi, Muhammad Abdul; Closs, S José

2016-06-01

Introduction Mixed-methods methodology, as the name suggests refers to mixing of elements of both qualitative and quantitative methodologies in a single study. In the past decade, mixed-methods methodology has gained popularity among healthcare researchers as it promises to bring together the strengths of both qualitative and quantitative approaches. Methodology A number of mixed-methods designs are available in the literature and the four most commonly used designs in healthcare research are: the convergent parallel design, the embedded design, the exploratory design, and the explanatory design. Each has its own unique advantages, challenges and procedures and selection of a particular design should be guided by the research question. Guidance on designing, conducting and reporting mixed-methods research is available in the literature, so it is advisable to adhere to this to ensure methodological rigour. When to use it is best suited when the research questions require: triangulating findings from different methodologies to explain a single phenomenon; clarifying the results of one method using another method; informing the design of one method based on the findings of another method, development of a scale/questionnaire and answering different research questions within a single study. Two case studies have been presented to illustrate possible applications of mixed-methods methodology. Limitations Possessing the necessary knowledge and skills to undertake qualitative and quantitative data collection, analysis, interpretation and integration remains the biggest challenge for researchers conducting mixed-methods studies. Sequential study designs are often time consuming, being in two (or more) phases whereas concurrent study designs may require more than one data collector to collect both qualitative and quantitative data at the same time.

Text-in-Context: A Method for Extracting Findings in Mixed-Methods Mixed Research Synthesis Studies

PubMed Central

Leeman, Jennifer; Knafl, Kathleen; Crandell, Jamie L.

2012-01-01

Aim Our purpose in this paper is to propose a new method for extracting findings from research reports included in mixed-methods mixed research synthesis studies. Background International initiatives in the domains of systematic review and evidence synthesis have been focused on broadening the conceptualization of evidence, increased methodological inclusiveness and the production of evidence syntheses that will be accessible to and usable by a wider range of consumers. Initiatives in the general mixed-methods research field have been focused on developing truly integrative approaches to data analysis and interpretation. Data source The data extraction challenges described here were encountered and the method proposed for addressing these challenges was developed, in the first year of the ongoing (2011–2016) study: Mixed-Methods Synthesis of Research on Childhood Chronic Conditions and Family. Discussion To preserve the text-in-context of findings in research reports, we describe a method whereby findings are transformed into portable statements that anchor results to relevant information about sample, source of information, time, comparative reference point, magnitude and significance and study-specific conceptions of phenomena. Implications for nursing The data extraction method featured here was developed specifically to accommodate mixed-methods mixed research synthesis studies conducted in nursing and other health sciences, but reviewers might find it useful in other kinds of research synthesis studies. Conclusion This data extraction method itself constitutes a type of integration to preserve the methodological context of findings when statements are read individually and in comparison to each other. PMID:22924808

Quantifying spatial distribution of spurious mixing in ocean models.

PubMed

Ilıcak, Mehmet

2016-12-01

Numerical mixing is inevitable for ocean models due to tracer advection schemes. Until now, there is no robust way to identify the regions of spurious mixing in ocean models. We propose a new method to compute the spatial distribution of the spurious diapycnic mixing in an ocean model. This new method is an extension of available potential energy density method proposed by Winters and Barkan (2013). We test the new method in lock-exchange and baroclinic eddies test cases. We can quantify the amount and the location of numerical mixing. We find high-shear areas are the main regions which are susceptible to numerical truncation errors. We also test the new method to quantify the numerical mixing in different horizontal momentum closures. We conclude that Smagorinsky viscosity has less numerical mixing than the Leith viscosity using the same non-dimensional constant.

Using Mixed Methods and Collaboration to Evaluate an Education and Public Outreach Program (Invited)

NASA Astrophysics Data System (ADS)

Shebby, S.; Shipp, S. S.

2013-12-01

Traditional indicators (such as the number of participants or Likert-type ratings of participant perceptions) are often used to provide stakeholders with basic information about program outputs and to justify funding decisions. However, use of qualitative methods can strengthen the reliability of these data and provide stakeholders with more meaningful information about program challenges, successes, and ultimate impacts (Stern, Stame, Mayne, Forss, David & Befani, 2012). In this session, presenters will discuss how they used a mixed methods evaluation to determine the impact of an education and public outreach (EPO) program. EPO efforts were intended to foster more effective, sustainable, and efficient utilization of science discoveries and learning experiences through three main goals 1) increase engagement and support by leveraging of resources, expertise, and best practices; 2) organize a portfolio of resources for accessibility, connectivity, and strategic growth; and 3) develop an infrastructure to support coordination. The evaluation team used a mixed methods design to conduct the evaluation. Presenters will first discuss five potential benefits of mixed methods designs: triangulation of findings, development, complementarity, initiation, and value diversity (Greene, Caracelli & Graham, 2005). They will next demonstrate how a 'mix' of methods, including artifact collection, surveys, interviews, focus groups, and vignettes, was included in the EPO project's evaluation design, providing specific examples of how alignment between the program theory and the evaluation plan was best achieved with a mixed methods approach. The presentation will also include an overview of different mixed methods approaches and information about important considerations when using a mixed methods design, such as selection of data collection methods and sources, and the timing and weighting of quantitative and qualitative methods (Creswell, 2003). Ultimately, this presentation will provide insight into how a mixed methods approach was used to provide stakeholders with important information about progress toward program goals. Creswell, J.W. (2003). Research design: Qualitative, quantitative, and mixed approaches. Thousand Oaks, CA: Sage. Greene, J. C., Caracelli, V. J., & Graham, W. D. (1989). Toward a conceptual framework for mixed-method evaluation designs. Educational Evaluation and Policy Analysis, 11(3), 255-274. Stern, E; Stame, N; Mayne, J; Forss, K; Davis, R & Befani, B (2012) Broadening the range of designs and methods for impact evaluation. Department for International Development.

Critical Communication Pedagogy and Service Learning in a Mixed-Method Communication Research Course

ERIC Educational Resources Information Center

Rudick, C. Kyle; Golsan, Kathryn B.; Freitag, Jennifer

2018-01-01

Course: Mixed-Method Communication Research Methods. Objective: The purpose of this semester-long activity is to provide students with opportunities to cultivate mixed-method communication research skills through a social justice-informed service-learning format. Completing this course, students will be able to: recognize the unique strengths of…

Reflections on Mixing Methods in Applied Linguistics Research

ERIC Educational Resources Information Center

Hashemi, Mohammad R.

2012-01-01

This commentary advocates the use of mixed methods research--that is the integration of qualitative and quantitative methods in a single study--in applied linguistics. Based on preliminary findings from a research project in progress, some reflections on the current practice of mixing methods as a new trend in applied linguistics are put forward.…

A Proposed Model of Retransformed Qualitative Data within a Mixed Methods Research Design

ERIC Educational Resources Information Center

Palladino, John M.

2009-01-01

Most models of mixed methods research design provide equal emphasis of qualitative and quantitative data analyses and interpretation. Other models stress one method more than the other. The present article is a discourse about the investigator's decision to employ a mixed method design to examine special education teachers' advocacy and…

Use of Mixed Methods Research in Research on Coronary Artery Disease, Diabetes Mellitus, and Hypertension: A Scoping Review.

PubMed

Campbell, David J T; Tam-Tham, Helen; Dhaliwal, Kirnvir K; Manns, Braden J; Hemmelgarn, Brenda R; Sanmartin, Claudia; King-Shier, Kathryn

2017-01-01

Mixed methods research, the use of both qualitative and quantitative methods within 1 program of study, is becoming increasingly popular to allow investigators to explore patient experiences (qualitative) and also measure outcomes (quantitative). Coronary artery disease and its risk factors are some of the most studied conditions; however, the extent to which mixed methods studies are being conducted in these content areas is unknown. We sought to comprehensively describe the characteristics of published mixed methods studies on coronary artery disease and major risk factors (diabetes mellitus and hypertension). We conducted a scoping review of the literature indexed in PubMed, Medline, EMBASE, and CINAHL. We identified 811 abstracts for screening, of which 254 articles underwent full-text review and 97 reports of 81 studies met criteria for inclusion. The majority of studies in this area were conducted in the past 10 years by nurse researchers from the United States and United Kingdom. Diabetes mellitus was the most common content area for mixed methods investigation (compared with coronary artery disease and hypertension). Most authors described their rationale for using mixed methods as complementarity and did not describe study priority or how they reconciled differences in methodological paradigms. Some mixed methods study designs were more commonly used than others, including concurrent timing and integration at the interpretation stage. Qualitative strands were most commonly descriptive studies using interviews for data collection. Quantitative strands were most commonly cross-sectional observational studies, which relied heavily on self-report data such as surveys and scales. Although mixed methods research is becoming increasingly popular in the area of coronary artery disease and its risk factors, many of the more advanced mixed methods, qualitative, and quantitative techniques have not been commonly used in these areas. © 2016 American Heart Association, Inc.

Three novel approaches to structural identifiability analysis in mixed-effects models.

PubMed

Janzén, David L I; Jirstrand, Mats; Chappell, Michael J; Evans, Neil D

2016-05-06

Structural identifiability is a concept that considers whether the structure of a model together with a set of input-output relations uniquely determines the model parameters. In the mathematical modelling of biological systems, structural identifiability is an important concept since biological interpretations are typically made from the parameter estimates. For a system defined by ordinary differential equations, several methods have been developed to analyse whether the model is structurally identifiable or otherwise. Another well-used modelling framework, which is particularly useful when the experimental data are sparsely sampled and the population variance is of interest, is mixed-effects modelling. However, established identifiability analysis techniques for ordinary differential equations are not directly applicable to such models. In this paper, we present and apply three different methods that can be used to study structural identifiability in mixed-effects models. The first method, called the repeated measurement approach, is based on applying a set of previously established statistical theorems. The second method, called the augmented system approach, is based on augmenting the mixed-effects model to an extended state-space form. The third method, called the Laplace transform mixed-effects extension, is based on considering the moment invariants of the systems transfer function as functions of random variables. To illustrate, compare and contrast the application of the three methods, they are applied to a set of mixed-effects models. Three structural identifiability analysis methods applicable to mixed-effects models have been presented in this paper. As method development of structural identifiability techniques for mixed-effects models has been given very little attention, despite mixed-effects models being widely used, the methods presented in this paper provides a way of handling structural identifiability in mixed-effects models previously not possible. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Development of a Mixed Methods Investigation of Process and Outcomes of Community-Based Participatory Research.

PubMed

Lucero, Julie; Wallerstein, Nina; Duran, Bonnie; Alegria, Margarita; Greene-Moton, Ella; Israel, Barbara; Kastelic, Sarah; Magarati, Maya; Oetzel, John; Pearson, Cynthia; Schulz, Amy; Villegas, Malia; White Hat, Emily R

2018-01-01

This article describes a mixed methods study of community-based participatory research (CBPR) partnership practices and the links between these practices and changes in health status and disparities outcomes. Directed by a CBPR conceptual model and grounded in indigenous-transformative theory, our nation-wide, cross-site study showcases the value of a mixed methods approach for better understanding the complexity of CBPR partnerships across diverse community and research contexts. The article then provides examples of how an iterative, integrated approach to our mixed methods analysis yielded enriched understandings of two key constructs of the model: trust and governance. Implications and lessons learned while using mixed methods to study CBPR are provided.

Mixed methods research in tobacco control with youth and young adults: A methodological review of current strategies

PubMed Central

Seaman, Elizabeth L.; Clark, Rachael S.; Plano Clark, Vicki L.

2017-01-01

Introduction Tobacco use among young people is a complex and serious global dilemma that demands innovative and diverse research approaches. The purpose of this methodological review was to examine the current use of mixed methods research in tobacco control with youth and young adult populations and to develop practical recommendations for tobacco control researchers interested in this methodology. Methods Using PubMed, we searched five peer-reviewed journals that publish tobacco control empirical literature for the use of mixed methods research to study young populations, age 12–25 years. Our team analyzed the features of each article in terms of tobacco control topic, population, youth engagement strategies, and several essential elements of mixed methods research. Results We identified 23 mixed methods studies published by authors from five different countries reported between 2004 and 2015. These 23 articles examined various topics that included tobacco use behavior, tobacco marketing and branding, and cessation among youth and young adults. The most common mixed methods approach was variations of the concurrent design in which the qualitative and quantitative strands were administered at the same time and given equal priority. This review documented several innovative applications of mixed methods research as well as challenges in the reporting of the complex research designs. Conclusions The use of mixed methods research in tobacco control has great potential for advancing the understanding of complex behavioral and sociocultural issues for all groups, especially youth and young adults. PMID:28841689

Invisible nursing research: thoughts about mixed methods research and nursing practice.

PubMed

Fawcett, Jacqueline

2015-04-01

In this this essay, the author addresses the close connection between mixed methods research and nursing practice. If the assertion that research and practice are parallel processes is accepted, then nursing practice may be considered "invisible mixed methods research," in that almost every encounter between a nurse and a patient involves collection and integration of qualitative (word) and quantitative (number) information that actually is single-case mixed methods research. © The Author(s) 2015.

A Digital Mixed Methods Research Design: Integrating Multimodal Analysis with Data Mining and Information Visualization for Big Data Analytics

ERIC Educational Resources Information Center

O'Halloran, Kay L.; Tan, Sabine; Pham, Duc-Son; Bateman, John; Vande Moere, Andrew

2018-01-01

This article demonstrates how a digital environment offers new opportunities for transforming qualitative data into quantitative data in order to use data mining and information visualization for mixed methods research. The digital approach to mixed methods research is illustrated by a framework which combines qualitative methods of multimodal…

A Mixed Methods Approach to Understanding School Counseling Program Evaluation: High School Counselors' Methods and Perceptions

ERIC Educational Resources Information Center

Aucoin, Jennifer Mangrum

2013-01-01

The purpose of this mixed methods concurrent triangulation study was to examine the program evaluation practices of high school counselors. A total of 294 high school counselors in Texas were assessed using a mixed methods concurrent triangulation design. A researcher-developed survey, the School Counseling Program Evaluation Questionnaire…

Demystifying Mixed Methods Research Design: A Review of the Literature

ERIC Educational Resources Information Center

Caruth, Gail D.

2013-01-01

Mixed methods research evolved in response to the observed limitations of both quantitative and qualitative designs and is a more complex method. The purpose of this paper was to examine mixed methods research in an attempt to demystify the design thereby allowing those less familiar with its design an opportunity to utilize it in future research.…

Problematic Preferences? A Mixed Method Examination of Principals' Preferences for Teacher Characteristics in Chicago

ERIC Educational Resources Information Center

Engel, Mimi

2013-01-01

Purpose: Relatively little is known about how principals make decisions about teacher hiring. This article uses mixed methods to examine what characteristics principals look for in teachers. Research Methods: Data were gathered using a mixed method approach, including in-depth interviews with a representative sample of 31 principals as well as an…

Mixing Qualitative and Quantitative Methods: Insights into Design and Analysis Issues

ERIC Educational Resources Information Center

Lieber, Eli

2009-01-01

This article describes and discusses issues related to research design and data analysis in the mixing of qualitative and quantitative methods. It is increasingly desirable to use multiple methods in research, but questions arise as to how best to design and analyze the data generated by mixed methods projects. I offer a conceptualization for such…

Mapping Mixed Methods Research: Methods, Measures, and Meaning

ERIC Educational Resources Information Center

Wheeldon, J.

2010-01-01

This article explores how concept maps and mind maps can be used as data collection tools in mixed methods research to combine the clarity of quantitative counts with the nuance of qualitative reflections. Based on more traditional mixed methods approaches, this article details how the use of pre/post concept maps can be used to design qualitative…

Explicating Metatheory for Mixed Methods Research in Educational Leadership: An Application of Habermas's "Theory of Communicative Action"

ERIC Educational Resources Information Center

Whiteman, Rodney S.

2015-01-01

Purpose: Mixed methods research can provide a fruitful line of inquiry for educational leadership, program evaluation, and policy analysis; however, mixed methods research requires a metatheory that allows for mixing what have traditionally been considered incompatible qualitative and quantitative inquiry. The purpose of this paper is to apply…

The Specificity of Observational Studies in Physical Activity and Sports Sciences: Moving Forward in Mixed Methods Research and Proposals for Achieving Quantitative and Qualitative Symmetry.

PubMed

Anguera, M Teresa; Camerino, Oleguer; Castañer, Marta; Sánchez-Algarra, Pedro; Onwuegbuzie, Anthony J

2017-01-01

Mixed methods studies are been increasingly applied to a diversity of fields. In this paper, we discuss the growing use-and enormous potential-of mixed methods research in the field of sport and physical activity. A second aim is to contribute to strengthening the characteristics of mixed methods research by showing how systematic observation offers rigor within a flexible framework that can be applied to a wide range of situations. Observational methodology is characterized by high scientific rigor and flexibility throughout its different stages and allows the objective study of spontaneous behavior in natural settings, with no external influence. Mixed methods researchers need to take bold yet thoughtful decisions regarding both substantive and procedural issues. We present three fundamental and complementary ideas to guide researchers in this respect: we show why studies of sport and physical activity that use a mixed methods research approach should be included in the field of mixed methods research, we highlight the numerous possibilities offered by observational methodology in this field through the transformation of descriptive data into quantifiable code matrices, and we discuss possible solutions for achieving true integration of qualitative and quantitative findings.

[The mixed design in nursing sciences or when a question of research calls for qualitative and quantitative strategies].

PubMed

Bourgault, Patricia; Gallagher, Frances; Michaud, Cécile; Saint-Cyr-Tribble, Denise

2010-12-01

The use of a mixed method research design raises many questions, especially regarding the paradigmatic position. With this paradigm, we may consider the mixed method design as the best way of answering a research question and the latter orients to one of the different subtypes of mixed method design. To illustrate the use of this kind of design, we propose a study such as conducted in nursing sciences. In this article, the challenges raised by the mixed method design, and the place of this type of research in nursing sciences is discussed.

A scoring system for appraising mixed methods research, and concomitantly appraising qualitative, quantitative and mixed methods primary studies in Mixed Studies Reviews.

PubMed

Pluye, Pierre; Gagnon, Marie-Pierre; Griffiths, Frances; Johnson-Lafleur, Janique

2009-04-01

A new form of literature review has emerged, Mixed Studies Review (MSR). These reviews include qualitative, quantitative and mixed methods studies. In the present paper, we examine MSRs in health sciences, and provide guidance on processes that should be included and reported. However, there are no valid and usable criteria for concomitantly appraising the methodological quality of the qualitative, quantitative and mixed methods studies. To propose criteria for concomitantly appraising the methodological quality of qualitative, quantitative and mixed methods studies or study components. A three-step critical review was conducted. 2322 references were identified in MEDLINE, and their titles and abstracts were screened; 149 potentially relevant references were selected and the full-text papers were examined; 59 MSRs were retained and scrutinized using a deductive-inductive qualitative thematic data analysis. This revealed three types of MSR: convenience, reproducible, and systematic. Guided by a proposal, we conducted a qualitative thematic data analysis of the quality appraisal procedures used in the 17 systematic MSRs (SMSRs). Of 17 SMSRs, 12 showed clear quality appraisal procedures with explicit criteria but no SMSR used valid checklists to concomitantly appraise qualitative, quantitative and mixed methods studies. In two SMSRs, criteria were developed following a specific procedure. Checklists usually contained more criteria than needed. In four SMSRs, a reliability assessment was described or mentioned. While criteria for quality appraisal were usually based on descriptors that require specific methodological expertise (e.g., appropriateness), no SMSR described the fit between reviewers' expertise and appraised studies. Quality appraisal usually resulted in studies being ranked by methodological quality. A scoring system is proposed for concomitantly appraising the methodological quality of qualitative, quantitative and mixed methods studies for SMSRs. This scoring system may also be used to appraise the methodological quality of qualitative, quantitative and mixed methods components of mixed methods research.

Critical Appraisal of Mixed Methods Studies

ERIC Educational Resources Information Center

Heyvaert, Mieke; Hannes, Karin; Maes, Bea; Onghena, Patrick

2013-01-01

In several subdomains of the social, behavioral, health, and human sciences, research questions are increasingly answered through mixed methods studies, combining qualitative and quantitative evidence and research elements. Accordingly, the importance of including those primary mixed methods research articles in systematic reviews grows. It is…

Research design: qualitative, quantitative and mixed methods approaches Research design: qualitative, quantitative and mixed methods approaches Creswell John W Sage 320 £29 0761924426 0761924426 [Formula: see text].

PubMed

2004-09-01

The second edition of Creswell's book has been significantly revised and updated. The author clearly sets out three approaches to research: quantitative, qualitative and mixed methods. As someone who has used mixed methods in my research, it is refreshing to read a textbook that addresses this. The differences between the approaches are clearly identified and a rationale for using each methodological stance provided.

Purists need not apply: the case for pragmatism in mixed methods research.

PubMed

Florczak, Kristine L

2014-10-01

The purpose of this column is to describe several different ways of conducting mixed method research. The paradigms that underpin both qualitative and quantitative research are also considered along with a cursory review of classical pragmatism as it relates conducting mixed methods studies. Finally, the idea of loosely coupled systems as a means to support mixed methods studies is proposed along with several caveats to researchers who desire to use this new way of obtaining knowledge. © The Author(s) 2014.

Introduction to special section of the Journal of Family Psychology, advances in mixed methods in family psychology: integrative and applied solutions for family science.

PubMed

Weisner, Thomas S; Fiese, Barbara H

2011-12-01

Mixed methods in family psychology refer to the systematic integration of qualitative and quantitative techniques to represent family processes and settings. Over the past decade, significant advances have been made in study design, analytic strategies, and technological support (such as software) that allow for the integration of quantitative and qualitative methods and for making appropriate inferences from mixed methods. This special section of the Journal of Family Psychology illustrates how mixed methods may be used to advance knowledge in family science through identifying important cultural differences in family structure, beliefs, and practices, and revealing patterns of family relationships to generate new measurement paradigms and inform clinical practice. Guidance is offered to advance mixed methods research in family psychology through sound principles of peer review.

Understanding the value of mixed methods research: the Children’s Safety Initiative-Emergency Medical Services

PubMed Central

Hansen, Matthew; O’Brien, Kerth; Meckler, Garth; Chang, Anna Marie; Guise, Jeanne-Marie

2016-01-01

Mixed methods research has significant potential to broaden the scope of emergency care and specifically emergency medical services investigation. Mixed methods studies involve the coordinated use of qualitative and quantitative research approaches to gain a fuller understanding of practice. By combining what is learnt from multiple methods, these approaches can help to characterise complex healthcare systems, identify the mechanisms of complex problems such as medical errors and understand aspects of human interaction such as communication, behaviour and team performance. Mixed methods approaches may be particularly useful for out-of-hospital care researchers because care is provided in complex systems where equipment, interpersonal interactions, societal norms, environment and other factors influence patient outcomes. The overall objectives of this paper are to (1) introduce the fundamental concepts and approaches of mixed methods research and (2) describe the interrelation and complementary features of the quantitative and qualitative components of mixed methods studies using specific examples from the Children’s Safety Initiative-Emergency Medical Services (CSI-EMS), a large National Institutes of Health-funded research project conducted in the USA. PMID:26949970

The MIXED framework: A novel approach to evaluating mixed-methods rigor.

PubMed

Eckhardt, Ann L; DeVon, Holli A

2017-10-01

Evaluation of rigor in mixed-methods (MM) research is a persistent challenge due to the combination of inconsistent philosophical paradigms, the use of multiple research methods which require different skill sets, and the need to combine research at different points in the research process. Researchers have proposed a variety of ways to thoroughly evaluate MM research, but each method fails to provide a framework that is useful for the consumer of research. In contrast, the MIXED framework is meant to bridge the gap between an academic exercise and practical assessment of a published work. The MIXED framework (methods, inference, expertise, evaluation, and design) borrows from previously published frameworks to create a useful tool for the evaluation of a published study. The MIXED framework uses an experimental eight-item scale that allows for comprehensive integrated assessment of MM rigor in published manuscripts. Mixed methods are becoming increasingly prevalent in nursing and healthcare research requiring researchers and consumers to address issues unique to MM such as evaluation of rigor. © 2017 John Wiley & Sons Ltd.

Changing Perspectives: Validation Framework Review of Examples of Mixed Methods Research into Culturally Relevant Teaching

ERIC Educational Resources Information Center

Hales, Patrick Dean

2016-01-01

Mixed methods research becomes more utilized in education research every year. As this pluralist paradigm begins to take hold, it becomes more and more necessary to take a critical eye to studies making use of different mixed methods approaches. An area of education research that has yet struggled to find a foothold with mixed methodology is…

Combining Qualitative and Quantitative Approaches: Some Arguments for Mixed Methods Research

ERIC Educational Resources Information Center

Lund, Thorleif

2012-01-01

One purpose of the present paper is to elaborate 4 general advantages of the mixed methods approach. Another purpose is to propose a 5-phase evaluation design, and to demonstrate its usefulness for mixed methods research. The account is limited to research on groups in need of treatment, i.e., vulnerable groups, and the advantages of mixed methods…

Development of a Mixed Methods Investigation of Process and Outcomes of Community-Based Participatory Research

PubMed Central

Lucero, Julie; Wallerstein, Nina; Duran, Bonnie; Alegria, Margarita; Greene-Moton, Ella; Israel, Barbara; Kastelic, Sarah; Magarati, Maya; Oetzel, John; Pearson, Cynthia; Schulz, Amy; Villegas, Malia; White Hat, Emily R.

2017-01-01

This article describes a mixed methods study of community-based participatory research (CBPR) partnership practices and the links between these practices and changes in health status and disparities outcomes. Directed by a CBPR conceptual model and grounded in indigenous-transformative theory, our nation-wide, cross-site study showcases the value of a mixed methods approach for better understanding the complexity of CBPR partnerships across diverse community and research contexts. The article then provides examples of how an iterative, integrated approach to our mixed methods analysis yielded enriched understandings of two key constructs of the model: trust and governance. Implications and lessons learned while using mixed methods to study CBPR are provided. PMID:29230152

Mixed method versus full top-down microcosting for organ recovery cost assessment in a French hospital group.

PubMed

Hrifach, Abdelbaste; Brault, Coralie; Couray-Targe, Sandrine; Badet, Lionel; Guerre, Pascale; Ganne, Christell; Serrier, Hassan; Labeye, Vanessa; Farge, Pierre; Colin, Cyrille

2016-12-01

The costing method used can change the results of economic evaluations. Choosing the appropriate method to assess the cost of organ recovery is an issue of considerable interest to health economists, hospitals, financial managers and policy makers in most developed countries. The main objective of this study was to compare a mixed method, combining top-down microcosting and bottom-up microcosting versus full top-down microcosting to assess the cost of organ recovery in a French hospital group. The secondary objective was to describe the cost of kidney, liver and pancreas recovery from French databases using the mixed method. The resources consumed for each donor were identified and valued using the proposed mixed method and compared to the full top-down microcosting approach. Data on kidney, liver and pancreas recovery were collected from a medico-administrative French database for the years 2010 and 2011. Related cost data were recovered from the hospital cost accounting system database for 2010 and 2011. Statistical significance was evaluated at P < 0.05. All the median costs for organ recovery differ significantly between the two costing methods (non-parametric test method; P < 0.01). Using the mixed method, the median cost for recovering kidneys was found to be €5155, liver recovery was €2528 and pancreas recovery was €1911. Using the full top-down microcosting method, median costs were found to be 21-36% lower than with the mixed method. The mixed method proposed appears to be a trade-off between feasibility and accuracy for the identification and valuation of cost components when calculating the cost of organ recovery in comparison to the full top-down microcosting approach.

Importance of mixed methods in pragmatic trials and dissemination and implementation research.

PubMed

Albright, Karen; Gechter, Katherine; Kempe, Allison

2013-01-01

With increased attention to the importance of translating research to clinical practice and policy, recent years have seen a proliferation of particular types of research, including pragmatic trials and dissemination and implementation research. Such research seeks to understand how and why interventions function in real-world settings, as opposed to highly controlled settings involving conditions not likely to be repeated outside the research study. Because understanding the context in which interventions are implemented is imperative for effective pragmatic trials and dissemination and implementation research, the use of mixed methods is critical to understanding trial results and the success or failure of implementation efforts. This article discusses a number of dimensions of mixed methods research, utilizing at least one qualitative method and at least one quantitative method, that may be helpful when designing projects or preparing grant proposals. Although the strengths and emphases of qualitative and quantitative approaches differ substantially, methods may be combined in a variety of ways to achieve a deeper level of understanding than can be achieved by one method alone. However, researchers must understand when and how to integrate the data as well as the appropriate order, priority, and purpose of each method. The ability to demonstrate an understanding of the rationale for and benefits of mixed methods research is increasingly important in today's competitive funding environment, and many funding agencies now expect applicants to include mixed methods in proposals. The increasing demand for mixed methods research necessitates broader methodological training and deepened collaboration between medical, clinical, and social scientists. Although a number of challenges to conducting and disseminating mixed methods research remain, the potential for insight generated by such work is substantial. Copyright © 2013 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Preparation of crotaline F-ab antivenom (CroFab) with automated mixing methods: in vitro observations.

PubMed

Vohra, Rais; Kelner, Michael; Clark, Richard F

2009-01-01

Crotaline Polyvalent Ovine Fab antivenom (CroFab, Savage Laboratories and Protherics Inc., Brentwood, TN, USA) preparation requires that the lyophilized powder be manually reconstituted before use. We compared automated methods for driving the product into solution with the standard manual method of reconstitution, and the effect of repeated rinsing of the product vial, on the per-vial availability of antivenom. Normal saline (NS, 10 mL) was added to 12 vials of expired CroFab. Vials were assigned in pairs to each of six mixing methods, including one pair mixed manually as recommended by the product package insert. Each vial's contents were diluted to a final volume of 75 mL of normal saline. Protein concentration was measured with a colorimetric assay. The fluid left in each vial was removed and the vial was washed with 10 mL NS. Total protein yield from each step was calculated. There was no significant change in protein yield among three of five automated mixing methods when compared to manual reconstitution. Repeat rinsing of the product vial with an additional 10 mLs of fluid added to the protein yield regardless of the mixing method used. We found slightly higher protein yields with all automated methods compared to manual mixing, but only two of five comparisons with the standard mixing method demonstrated statistical significance. However, for all methods tested, the addition of a second rinsing and recovery step increased the amount of protein recovered considerably, presumably by allowing solution of protein trapped in the foamy residues. Automated mixing methods and repeat rinsing of the product vial may allow higher protein yields in the preparation of CroFab antivenom.

Mixed ionic-electronic conductor-based radiation detectors and methods of fabrication

DOEpatents

Conway, Adam; Beck, Patrick R; Graff, Robert T; Nelson, Art; Nikolic, Rebecca J; Payne, Stephen A; Voss, Lars; Kim, Hadong

2015-04-07

A method of fabricating a mixed ionic-electronic conductor (e.g. TlBr)-based radiation detector having halide-treated surfaces and associated methods of fabrication, which controls polarization of the mixed ionic-electronic MIEC material to improve stability and operational lifetime.

Integrating Quantitative and Qualitative Results in Health Science Mixed Methods Research Through Joint Displays

PubMed Central

Guetterman, Timothy C.; Fetters, Michael D.; Creswell, John W.

2015-01-01

PURPOSE Mixed methods research is becoming an important methodology to investigate complex health-related topics, yet the meaningful integration of qualitative and quantitative data remains elusive and needs further development. A promising innovation to facilitate integration is the use of visual joint displays that bring data together visually to draw out new insights. The purpose of this study was to identify exemplar joint displays by analyzing the various types of joint displays being used in published articles. METHODS We searched for empirical articles that included joint displays in 3 journals that publish state-of-the-art mixed methods research. We analyzed each of 19 identified joint displays to extract the type of display, mixed methods design, purpose, rationale, qualitative and quantitative data sources, integration approaches, and analytic strategies. Our analysis focused on what each display communicated and its representation of mixed methods analysis. RESULTS The most prevalent types of joint displays were statistics-by-themes and side-by-side comparisons. Innovative joint displays connected findings to theoretical frameworks or recommendations. Researchers used joint displays for convergent, explanatory sequential, exploratory sequential, and intervention designs. We identified exemplars for each of these designs by analyzing the inferences gained through using the joint display. Exemplars represented mixed methods integration, presented integrated results, and yielded new insights. CONCLUSIONS Joint displays appear to provide a structure to discuss the integrated analysis and assist both researchers and readers in understanding how mixed methods provides new insights. We encourage researchers to use joint displays to integrate and represent mixed methods analysis and discuss their value. PMID:26553895

Mixed methods research in tobacco control with youth and young adults: A methodological review of current strategies.

PubMed

Fryer, Craig S; Seaman, Elizabeth L; Clark, Rachael S; Plano Clark, Vicki L

2017-01-01

Tobacco use among young people is a complex and serious global dilemma that demands innovative and diverse research approaches. The purpose of this methodological review was to examine the current use of mixed methods research in tobacco control with youth and young adult populations and to develop practical recommendations for tobacco control researchers interested in this methodology. Using PubMed, we searched five peer-reviewed journals that publish tobacco control empirical literature for the use of mixed methods research to study young populations, age 12-25 years. Our team analyzed the features of each article in terms of tobacco control topic, population, youth engagement strategies, and several essential elements of mixed methods research. We identified 23 mixed methods studies published by authors from five different countries reported between 2004 and 2015. These 23 articles examined various topics that included tobacco use behavior, tobacco marketing and branding, and cessation among youth and young adults. The most common mixed methods approach was variations of the concurrent design in which the qualitative and quantitative strands were administered at the same time and given equal priority. This review documented several innovative applications of mixed methods research as well as challenges in the reporting of the complex research designs. The use of mixed methods research in tobacco control has great potential for advancing the understanding of complex behavioral and sociocultural issues for all groups, especially youth and young adults.

Advancing the study of violence against women using mixed methods: integrating qualitative methods into a quantitative research program.

PubMed

Testa, Maria; Livingston, Jennifer A; VanZile-Tamsen, Carol

2011-02-01

A mixed methods approach, combining quantitative with qualitative data methods and analysis, offers a promising means of advancing the study of violence. Integrating semi-structured interviews and qualitative analysis into a quantitative program of research on women's sexual victimization has resulted in valuable scientific insight and generation of novel hypotheses for testing. This mixed methods approach is described and recommendations for integrating qualitative data into quantitative research are provided.

Mixed-Methods Research Methodologies

ERIC Educational Resources Information Center

Terrell, Steven R.

2012-01-01

Mixed-Method studies have emerged from the paradigm wars between qualitative and quantitative research approaches to become a widely used mode of inquiry. Depending on choices made across four dimensions, mixed-methods can provide an investigator with many design choices which involve a range of sequential and concurrent strategies. Defining…

A Mixed-Methods Exploration of an Environment for Learning Computer Programming

ERIC Educational Resources Information Center

Mather, Richard

2015-01-01

A mixed-methods approach is evaluated for exploring collaborative behaviour, acceptance and progress surrounding an interactive technology for learning computer programming. A review of literature reveals a compelling case for using mixed-methods approaches when evaluating technology-enhanced-learning environments. Here, ethnographic approaches…

Mixed time integration methods for transient thermal analysis of structures

NASA Technical Reports Server (NTRS)

Liu, W. K.

1982-01-01

The computational methods used to predict and optimize the thermal structural behavior of aerospace vehicle structures are reviewed. In general, two classes of algorithms, implicit and explicit, are used in transient thermal analysis of structures. Each of these two methods has its own merits. Due to the different time scales of the mechanical and thermal responses, the selection of a time integration method can be a different yet critical factor in the efficient solution of such problems. Therefore mixed time integration methods for transient thermal analysis of structures are being developed. The computer implementation aspects and numerical evaluation of these mixed time implicit-explicit algorithms in thermal analysis of structures are presented. A computationally useful method of estimating the critical time step for linear quadrilateral element is also given. Numerical tests confirm the stability criterion and accuracy characteristics of the methods. The superiority of these mixed time methods to the fully implicit method or the fully explicit method is also demonstrated.

Mixed time integration methods for transient thermal analysis of structures

NASA Technical Reports Server (NTRS)

Liu, W. K.

1983-01-01

The computational methods used to predict and optimize the thermal-structural behavior of aerospace vehicle structures are reviewed. In general, two classes of algorithms, implicit and explicit, are used in transient thermal analysis of structures. Each of these two methods has its own merits. Due to the different time scales of the mechanical and thermal responses, the selection of a time integration method can be a difficult yet critical factor in the efficient solution of such problems. Therefore mixed time integration methods for transient thermal analysis of structures are being developed. The computer implementation aspects and numerical evaluation of these mixed time implicit-explicit algorithms in thermal analysis of structures are presented. A computationally-useful method of estimating the critical time step for linear quadrilateral element is also given. Numerical tests confirm the stability criterion and accuracy characteristics of the methods. The superiority of these mixed time methods to the fully implicit method or the fully explicit method is also demonstrated.

Implementing Quality Criteria in Designing and Conducting a Sequential Quan [right arrow] Qual Mixed Methods Study of Student Engagement with Learning Applied Research Methods Online

ERIC Educational Resources Information Center

Ivankova, Nataliya V.

2014-01-01

In spite of recent methodological developments related to quality assurance in mixed methods research, practical examples of how to implement quality criteria in designing and conducting sequential QUAN [right arrow] QUAL mixed methods studies to ensure the process is systematic and rigorous remain scarce. This article discusses a three-step…

Points of Convergence in Music Education: The Use of Data Labels as a Strategy for Mixed Methods Integration

ERIC Educational Resources Information Center

Fitzpatrick, Kate R.

2016-01-01

Although the mixing of quantitative and qualitative data is an essential component of mixed methods research, the process of integrating both types of data in meaningful ways can be challenging. The purpose of this article is to describe the use of data labels in mixed methods research as a technique for the integration of qualitative and…

Development of a Hybrid RANS/LES Method for Compressible Mixing Layer Simulations

NASA Technical Reports Server (NTRS)

Georgiadis, Nicholas J.; Alexander, J. Iwan D.; Reshotko, Eli

2001-01-01

A hybrid method has been developed for simulations of compressible turbulent mixing layers. Such mixing layers dominate the flows in exhaust systems of modem day aircraft and also those of hypersonic vehicles currently under development. The hybrid method uses a Reynolds-averaged Navier-Stokes (RANS) procedure to calculate wall bounded regions entering a mixing section, and a Large Eddy Simulation (LES) procedure to calculate the mixing dominated regions. A numerical technique was developed to enable the use of the hybrid RANS/LES method on stretched, non-Cartesian grids. The hybrid RANS/LES method is applied to a benchmark compressible mixing layer experiment. Preliminary two-dimensional calculations are used to investigate the effects of axial grid density and boundary conditions. Actual LES calculations, performed in three spatial directions, indicated an initial vortex shedding followed by rapid transition to turbulence, which is in agreement with experimental observations.

What is so new about mixed methods?

PubMed

Pelto, Pertti J

2015-06-01

In this article, I dispute claims that mixed methods research emerged only recently in the social sciences. I argue that some anthropologists and sociologists (and others) have used mixed methods in fieldwork for at least 80 years, and there are studies from early in the 20th century that clearly fall within the definition of "mixed methods." I explore some of the history of the mixing of qualitative and quantitative data in earlier ethnographic works and show that in some sectors of social science research, the "emergence" and proliferation of mixed methods were particularly notable around the middle of the 20th century. Furthermore, concerning issues about "paradigms of research" in the social sciences, I identify some of the types of research in which the mixing of QUAL and QUAN approaches was more likely to occur. I suggest that some of the literature about research paradigms has involved a certain amount of "myth-making" in connection with descriptions of qualitative and quantitative research assumptions and styles. © The Author(s) 2015.

Assessing and evaluating multidisciplinary translational teams: a mixed methods approach.

PubMed

Wooten, Kevin C; Rose, Robert M; Ostir, Glenn V; Calhoun, William J; Ameredes, Bill T; Brasier, Allan R

2014-03-01

A case report illustrates how multidisciplinary translational teams can be assessed using outcome, process, and developmental types of evaluation using a mixed-methods approach. Types of evaluation appropriate for teams are considered in relation to relevant research questions and assessment methods. Logic models are applied to scientific projects and team development to inform choices between methods within a mixed-methods design. Use of an expert panel is reviewed, culminating in consensus ratings of 11 multidisciplinary teams and a final evaluation within a team-type taxonomy. Based on team maturation and scientific progress, teams were designated as (a) early in development, (b) traditional, (c) process focused, or (d) exemplary. Lessons learned from data reduction, use of mixed methods, and use of expert panels are explored.

Mapping the Mixed Methods–Mixed Research Synthesis Terrain

PubMed Central

Sandelowski, Margarete; Voils, Corrine I.; Leeman, Jennifer; Crandell, Jamie L.

2012-01-01

Mixed methods–mixed research synthesis is a form of systematic review in which the findings of qualitative and quantitative studies are integrated via qualitative and/or quantitative methods. Although methodological advances have been made, efforts to differentiate research synthesis methods have been too focused on methods and not focused enough on the defining logics of research synthesis—each of which may be operationalized in different ways—or on the research findings themselves that are targeted for synthesis. The conduct of mixed methods–mixed research synthesis studies may more usefully be understood in terms of the logics of aggregation and configuration. Neither logic is preferable to the other nor tied exclusively to any one method or to any one side of the qualitative/quantitative binary. PMID:23066379

Mixed-Methods Design in Biology Education Research: Approach and Uses

ERIC Educational Resources Information Center

Warfa, Abdi-Rizak M.

2016-01-01

Educational research often requires mixing different research methodologies to strengthen findings, better contextualize or explain results, or minimize the weaknesses of a single method. This article provides practical guidelines on how to conduct such research in biology education, with a focus on mixed-methods research (MMR) that uses both…

Identity, Intersectionality, and Mixed-Methods Approaches

ERIC Educational Resources Information Center

Harper, Casandra E.

2011-01-01

In this article, the author argues that current strategies to study and understand students' identities fall short of fully capturing their complexity. A multi-dimensional perspective and a mixed-methods approach can reveal nuance that is missed with current approaches. The author offers an illustration of how mixed-methods research can promote a…

Mixing Methods in Assessing Coaches' Decision Making

ERIC Educational Resources Information Center

Vergeer, Ineke; Lyle, John

2007-01-01

Mixing methods has recently achieved respectability as an appropriate approach to research design, offering a variety of advantages (Tashakkori & Teddlie, 2003). The purpose of this paper is to outline and evaluate a mixed methods approach within the domain of coaches' decision making. Illustrated with data from a policy-capturing study on…

Designing, Teaching, and Evaluating Two Complementary Mixed Methods Research Courses

ERIC Educational Resources Information Center

Christ, Thomas W.

2009-01-01

Teaching mixed methods research is difficult. This longitudinal explanatory study examined how two classes were designed, taught, and evaluated. Curriculum, Research, and Teaching (EDCS-606) and Mixed Methods Research (EDCS-780) used a research proposal generation process to highlight the importance of the purpose, research question and…

Mixed Methods Approaches in Family Science Research

ERIC Educational Resources Information Center

Plano Clark, Vicki L.; Huddleston-Casas, Catherine A.; Churchill, Susan L.; Green, Denise O'Neil; Garrett, Amanda L.

2008-01-01

The complex phenomena of interest to family scientists require the use of quantitative and qualitative approaches. Researchers across the social sciences are now turning to mixed methods designs that combine these two approaches. Mixed methods research has great promise for addressing family science topics, but only if researchers understand the…

Mixed Methods in Intervention Research: Theory to Adaptation

ERIC Educational Resources Information Center

Nastasi, Bonnie K.; Hitchcock, John; Sarkar, Sreeroopa; Burkholder, Gary; Varjas, Kristen; Jayasena, Asoka

2007-01-01

The purpose of this article is to demonstrate the application of mixed methods research designs to multiyear programmatic research and development projects whose goals include integration of cultural specificity when generating or translating evidence-based practices. The authors propose a set of five mixed methods designs related to different…

A New Expanded Mixed Element Method for Convection-Dominated Sobolev Equation

PubMed Central

Wang, Jinfeng; Li, Hong; Fang, Zhichao

2014-01-01

We propose and analyze a new expanded mixed element method, whose gradient belongs to the simple square integrable space instead of the classical H(div; Ω) space of Chen's expanded mixed element method. We study the new expanded mixed element method for convection-dominated Sobolev equation, prove the existence and uniqueness for finite element solution, and introduce a new expanded mixed projection. We derive the optimal a priori error estimates in L 2-norm for the scalar unknown u and a priori error estimates in (L 2)2-norm for its gradient λ and its flux σ. Moreover, we obtain the optimal a priori error estimates in H 1-norm for the scalar unknown u. Finally, we obtained some numerical results to illustrate efficiency of the new method. PMID:24701153

Deconstructing the complexity of substance use among young men who have sex with men (YMSM) by optimizing the role of qualitative strategies in a mixed methods study.

PubMed

Kubicek, Katrina; Weiss, George; Iverson, Ellen F; Kipke, Michele D

2010-04-01

Qualitative data can be a powerful tool in developing interventions for substance use and other HIV-risk behaviors. Mixed methods design offers researchers the ability to obtain data that provides both breadth and depth to their research questions. However, the integration of qualitative data in mixed methods research has been limited. This paper describes the qualitative study design of the Healthy Young Men's Study, a longitudinal mixed method study with an ethnically diverse cohort of young men who have sex with men (YMSM) (N = 526) in Los Angeles. Integral to this discussion is how a mixed methods study can address common challenges such as sampling, representation and integration of both datasets.

A Mixed Methods Approach to Equity and Justice Research: Insights from Research on Children's Reasoning About Economic Inequality.

PubMed

Mistry, Rashmita S; White, Elizabeth S; Chow, Kirby A; Griffin, Katherine M; Nenadal, Lindsey

2016-01-01

Mixed methods research approaches are gaining traction across various social science disciplines, including among developmental scientists. In this chapter, we discuss the utility of a mixed methods research approach in examining issues related to equity and justice. We incorporate a brief overview of quantitative and qualitative monomethod research approaches in our larger discussion of the advantages, procedures, and considerations of employing a mixed methods design to advance developmental science from an equity and justice perspective. To better illustrate the theoretical and practical significance of a mixed methods research approach, we include examples of research conducted on children and adolescents' conceptions of economic inequality as one example of developmental science research with an equity and justice frame. © 2016 Elsevier Inc. All rights reserved.

Deconstructing the complexity of substance use among young men who have sex with men (YMSM) by optimizing the role of qualitative strategies in a mixed methods study

PubMed Central

Kubicek, Katrina; Weiss, George; Iverson, Ellen F.; Kipke, Michele D.

2010-01-01

Qualitative data can be a powerful tool in developing interventions for substance use and other HIV-risk behaviors. Mixed-methods design offers researchers the ability to obtain data that provides both breadth and depth to their research. However, the integration of qualitative data in mixed-methods research has been limited. This paper describes the qualitative design of the Healthy Young Men’s Study, a longitudinal mixed-method study with an ethnically diverse cohort of young men who have sex with men (YMSM) (N=526) in Los Angeles. Integral to this discussion is how a mixed-methods study can address common challenges such as sampling, representation and integration. PMID:20222783

The Specificity of Observational Studies in Physical Activity and Sports Sciences: Moving Forward in Mixed Methods Research and Proposals for Achieving Quantitative and Qualitative Symmetry

PubMed Central

Anguera, M. Teresa; Camerino, Oleguer; Castañer, Marta; Sánchez-Algarra, Pedro; Onwuegbuzie, Anthony J.

2017-01-01

Mixed methods studies are been increasingly applied to a diversity of fields. In this paper, we discuss the growing use—and enormous potential—of mixed methods research in the field of sport and physical activity. A second aim is to contribute to strengthening the characteristics of mixed methods research by showing how systematic observation offers rigor within a flexible framework that can be applied to a wide range of situations. Observational methodology is characterized by high scientific rigor and flexibility throughout its different stages and allows the objective study of spontaneous behavior in natural settings, with no external influence. Mixed methods researchers need to take bold yet thoughtful decisions regarding both substantive and procedural issues. We present three fundamental and complementary ideas to guide researchers in this respect: we show why studies of sport and physical activity that use a mixed methods research approach should be included in the field of mixed methods research, we highlight the numerous possibilities offered by observational methodology in this field through the transformation of descriptive data into quantifiable code matrices, and we discuss possible solutions for achieving true integration of qualitative and quantitative findings. PMID:29312061

Alternating direction implicit methods for parabolic equations with a mixed derivative

NASA Technical Reports Server (NTRS)

Beam, R. M.; Warming, R. F.

1980-01-01

Alternating direction implicit (ADI) schemes for two-dimensional parabolic equations with a mixed derivative are constructed by using the class of all A(0)-stable linear two-step methods in conjunction with the method of approximate factorization. The mixed derivative is treated with an explicit two-step method which is compatible with an implicit A(0)-stable method. The parameter space for which the resulting ADI schemes are second-order accurate and unconditionally stable is determined. Some numerical examples are given.

Alternating direction implicit methods for parabolic equations with a mixed derivative

NASA Technical Reports Server (NTRS)

Beam, R. M.; Warming, R. F.

1979-01-01

Alternating direction implicit (ADI) schemes for two-dimensional parabolic equations with a mixed derivative are constructed by using the class of all A sub 0-stable linear two-step methods in conjunction with the method of approximation factorization. The mixed derivative is treated with an explicit two-step method which is compatible with an implicit A sub 0-stable method. The parameter space for which the resulting ADI schemes are second order accurate and unconditionally stable is determined. Some numerical examples are given.

Compiled visualization with IPI method for analysing of liquid liquid mixing process

NASA Astrophysics Data System (ADS)

Jasikova, Darina; Kotek, Michal; Kysela, Bohus; Sulc, Radek; Kopecky, Vaclav

2018-06-01

The article deals with the research of mixing process using visualization techniques and IPI method. Characteristics of the size distribution and the evolution of two liquid-liquid phase's disintegration were studied. A methodology has been proposed for visualization and image analysis of data acquired during the initial phase of the mixing process. IPI method was used for subsequent detailed study of the disintegrated droplets. The article describes advantages of usage of appropriate method, presents the limits of each method, and compares them.

ADVANCING THE STUDY OF VIOLENCE AGAINST WOMEN USING MIXED METHODS: INTEGRATING QUALITATIVE METHODS INTO A QUANTITATIVE RESEARCH PROGRAM

PubMed Central

Testa, Maria; Livingston, Jennifer A.; VanZile-Tamsen, Carol

2011-01-01

A mixed methods approach, combining quantitative with qualitative data methods and analysis, offers a promising means of advancing the study of violence. Integrating semi-structured interviews and qualitative analysis into a quantitative program of research on women’s sexual victimization has resulted in valuable scientific insight and generation of novel hypotheses for testing. This mixed methods approach is described and recommendations for integrating qualitative data into quantitative research are provided. PMID:21307032

Integrating Quantitative and Qualitative Results in Health Science Mixed Methods Research Through Joint Displays.

PubMed

Guetterman, Timothy C; Fetters, Michael D; Creswell, John W

2015-11-01

Mixed methods research is becoming an important methodology to investigate complex health-related topics, yet the meaningful integration of qualitative and quantitative data remains elusive and needs further development. A promising innovation to facilitate integration is the use of visual joint displays that bring data together visually to draw out new insights. The purpose of this study was to identify exemplar joint displays by analyzing the various types of joint displays being used in published articles. We searched for empirical articles that included joint displays in 3 journals that publish state-of-the-art mixed methods research. We analyzed each of 19 identified joint displays to extract the type of display, mixed methods design, purpose, rationale, qualitative and quantitative data sources, integration approaches, and analytic strategies. Our analysis focused on what each display communicated and its representation of mixed methods analysis. The most prevalent types of joint displays were statistics-by-themes and side-by-side comparisons. Innovative joint displays connected findings to theoretical frameworks or recommendations. Researchers used joint displays for convergent, explanatory sequential, exploratory sequential, and intervention designs. We identified exemplars for each of these designs by analyzing the inferences gained through using the joint display. Exemplars represented mixed methods integration, presented integrated results, and yielded new insights. Joint displays appear to provide a structure to discuss the integrated analysis and assist both researchers and readers in understanding how mixed methods provides new insights. We encourage researchers to use joint displays to integrate and represent mixed methods analysis and discuss their value. © 2015 Annals of Family Medicine, Inc.

Identification of DNA-Binding Proteins Using Mixed Feature Representation Methods.

PubMed

Qu, Kaiyang; Han, Ke; Wu, Song; Wang, Guohua; Wei, Leyi

2017-09-22

DNA-binding proteins play vital roles in cellular processes, such as DNA packaging, replication, transcription, regulation, and other DNA-associated activities. The current main prediction method is based on machine learning, and its accuracy mainly depends on the features extraction method. Therefore, using an efficient feature representation method is important to enhance the classification accuracy. However, existing feature representation methods cannot efficiently distinguish DNA-binding proteins from non-DNA-binding proteins. In this paper, a multi-feature representation method, which combines three feature representation methods, namely, K-Skip-N-Grams, Information theory, and Sequential and structural features (SSF), is used to represent the protein sequences and improve feature representation ability. In addition, the classifier is a support vector machine. The mixed-feature representation method is evaluated using 10-fold cross-validation and a test set. Feature vectors, which are obtained from a combination of three feature extractions, show the best performance in 10-fold cross-validation both under non-dimensional reduction and dimensional reduction by max-relevance-max-distance. Moreover, the reduced mixed feature method performs better than the non-reduced mixed feature technique. The feature vectors, which are a combination of SSF and K-Skip-N-Grams, show the best performance in the test set. Among these methods, mixed features exhibit superiority over the single features.

Multivariate statistical approach to estimate mixing proportions for unknown end members

USGS Publications Warehouse

Valder, Joshua F.; Long, Andrew J.; Davis, Arden D.; Kenner, Scott J.

2012-01-01

A multivariate statistical method is presented, which includes principal components analysis (PCA) and an end-member mixing model to estimate unknown end-member hydrochemical compositions and the relative mixing proportions of those end members in mixed waters. PCA, together with the Hotelling T2 statistic and a conceptual model of groundwater flow and mixing, was used in selecting samples that best approximate end members, which then were used as initial values in optimization of the end-member mixing model. This method was tested on controlled datasets (i.e., true values of estimates were known a priori) and found effective in estimating these end members and mixing proportions. The controlled datasets included synthetically generated hydrochemical data, synthetically generated mixing proportions, and laboratory analyses of sample mixtures, which were used in an evaluation of the effectiveness of this method for potential use in actual hydrological settings. For three different scenarios tested, correlation coefficients (R2) for linear regression between the estimated and known values ranged from 0.968 to 0.993 for mixing proportions and from 0.839 to 0.998 for end-member compositions. The method also was applied to field data from a study of end-member mixing in groundwater as a field example and partial method validation.

A Mixed-Methods Comparison of Classroom Context during Food, Health & Choices, a Childhood Obesity Prevention Intervention

ERIC Educational Resources Information Center

Burgermaster, Marissa; Koroly, Jenna; Contento, Isobel; Koch, Pamela; Gray, Heewon L.

2017-01-01

Background: Schools are frequent settings for childhood obesity prevention; however, intervention results are mixed. Classroom context may hold important clues to improving these interventions. Methods: We used mixed methods to examine classroom context during a curriculum intervention taught by trained instructors in fifth grade classrooms. We…

Commentary: Using Mixed Methods to Transform Special Education Research

ERIC Educational Resources Information Center

Trainor, Audrey A.

2011-01-01

Klingner and Boardman (this issue) offer a cogent and compelling argument for opening the door for the acceptance and use of mixed methods in special education research. Self-identifying as pragmatists, they embody this paradigmatic view by focusing on the utility, efficacy, and accuracy of mixed methods, an argument that should appeal to the…

A Mixed Methods Portrait of Urban Instrumental Music Teaching

ERIC Educational Resources Information Center

Fitzpatrick, Kate R.

2011-01-01

The purpose of this mixed methods study was to learn about the ways that instrumental music teachers in Chicago navigated the urban landscape. The design of the study most closely resembles Creswell and Plano Clark's (2007) two-part Triangulation Convergence Mixed Methods Design, with the addition of an initial exploratory focus group component.…

Triangulation, Respondent Validation, and Democratic Participation in Mixed Methods Research

ERIC Educational Resources Information Center

Torrance, Harry

2012-01-01

Over the past 10 years or so the "Field" of "Mixed Methods Research" (MMR) has increasingly been exerting itself as something separate, novel, and significant, with some advocates claiming paradigmatic status. Triangulation is an important component of mixed methods designs. Triangulation has its origins in attempts to validate research findings…

THREE-POINT BACKWARD FINITE DIFFERENCE METHOD FOR SOLVING A SYSTEM OF MIXED HYPERBOLIC-PARABOLIC PARTIAL DIFFERENTIAL EQUATIONS. (R825549C019)

EPA Science Inventory

A three-point backward finite-difference method has been derived for a system of mixed hyperbolic_¯¯parabolic (convection_¯¯diffusion) partial differential equations (mixed PDEs). The method resorts to the three-point backward differenci...

Teacher Professionalism and Team Performance Pay: A Mixed Methods Study

ERIC Educational Resources Information Center

Wells, Pamela; Combs, Julie P.; Bustamante, Rebecca M.

2012-01-01

The purpose of this mixed methods research study was to explore teachers' perceptions of their professional behaviors when they worked in schools that awarded team performance pay. Teachers' archival responses from two questionnaires were analyzed using mixed methods data analysis techniques (Year 1, n = 368; Year 2, n = 649). Most teachers had…

Assessing and Evaluating Multidisciplinary Translational Teams: A Mixed Methods Approach

PubMed Central

Wooten, Kevin C.; Rose, Robert M.; Ostir, Glenn V.; Calhoun, William J.; Ameredes, Bill T.; Brasier, Allan R.

2014-01-01

A case report illustrates how multidisciplinary translational teams can be assessed using outcome, process, and developmental types of evaluation using a mixed methods approach. Types of evaluation appropriate for teams are considered in relation to relevant research questions and assessment methods. Logic models are applied to scientific projects and team development to inform choices between methods within a mixed methods design. Use of an expert panel is reviewed, culminating in consensus ratings of 11 multidisciplinary teams and a final evaluation within a team type taxonomy. Based on team maturation and scientific progress, teams were designated as: a) early in development, b) traditional, c) process focused, or d) exemplary. Lessons learned from data reduction, use of mixed methods, and use of expert panels are explored. PMID:24064432

A comparative study of different methods for calculating electronic transition rates

NASA Astrophysics Data System (ADS)

Kananenka, Alexei A.; Sun, Xiang; Schubert, Alexander; Dunietz, Barry D.; Geva, Eitan

2018-03-01

We present a comprehensive comparison of the following mixed quantum-classical methods for calculating electronic transition rates: (1) nonequilibrium Fermi's golden rule, (2) mixed quantum-classical Liouville method, (3) mean-field (Ehrenfest) mixed quantum-classical method, and (4) fewest switches surface-hopping method (in diabatic and adiabatic representations). The comparison is performed on the Garg-Onuchic-Ambegaokar benchmark charge-transfer model, over a broad range of temperatures and electronic coupling strengths, with different nonequilibrium initial states, in the normal and inverted regimes. Under weak to moderate electronic coupling, the nonequilibrium Fermi's golden rule rates are found to be in good agreement with the rates obtained via the mixed quantum-classical Liouville method that coincides with the fully quantum-mechanically exact results for the model system under study. Our results suggest that the nonequilibrium Fermi's golden rule can serve as an inexpensive yet accurate alternative to Ehrenfest and the fewest switches surface-hopping methods.

A time dependent mixing model to close PDF equations for transport in heterogeneous aquifers

NASA Astrophysics Data System (ADS)

Schüler, L.; Suciu, N.; Knabner, P.; Attinger, S.

2016-10-01

Probability density function (PDF) methods are a promising alternative to predicting the transport of solutes in groundwater under uncertainty. They make it possible to derive the evolution equations of the mean concentration and the concentration variance, used in moment methods. The mixing model, describing the transport of the PDF in concentration space, is essential for both methods. Finding a satisfactory mixing model is still an open question and due to the rather elaborate PDF methods, a difficult undertaking. Both the PDF equation and the concentration variance equation depend on the same mixing model. This connection is used to find and test an improved mixing model for the much easier to handle concentration variance. Subsequently, this mixing model is transferred to the PDF equation and tested. The newly proposed mixing model yields significantly improved results for both variance modelling and PDF modelling.

Mixed-Methods Research in the Discipline of Nursing.

PubMed

Beck, Cheryl Tatano; Harrison, Lisa

2016-01-01

In this review article, we examined the prevalence and characteristics of 294 mixed-methods studies in the discipline of nursing. Creswell and Plano Clark's typology was most frequently used along with concurrent timing. Bivariate statistics was most often the highest level of statistics reported in the results. As for qualitative data analysis, content analysis was most frequently used. The majority of nurse researchers did not specifically address the purpose, paradigm, typology, priority, timing, interaction, or integration of their mixed-methods studies. Strategies are suggested for improving the design, conduct, and reporting of mixed-methods studies in the discipline of nursing.

A Trojan horse for positivism?: a critique of mixed methods research.

PubMed

Giddings, Lynne S; Grant, Barbara M

2007-01-01

Mixed methods research is captured by a pragmatically inflected form of postpositivism. Although it passes for an alternative methodological movement that purports to breach the divide between qualitative and quantitative research, most mixed methods studies favor the forms of analysis and truth finding associated with positivism. We anticipate a move away from exploring more philosophical questions or undertaking modes of enquiry that challenge the status quo. At the same time, we recognize that mixed methods research offers particular strengths and that, although it serves as a Trojan Horse for positivism, it may productively carry other paradigmatic passengers.

Changes in contraceptive use and method mix in Pakistan: 1990-91 to 2006-07.

PubMed

Carton, Thomas W; Agha, Sohail

2012-03-01

To determine (a) whether the influence of the determinants of family planning use in Pakistan changed between 1990-91 and 2006-07, and (b) if these changes were associated with changes in the method mix. Data from the Pakistan Demographic and Health Surveys (PDHS) of 1990-91 and 2006-07 were used in the analyses. Data on 5184 married, non-pregnant, fecund women in 1990-91 and 8041 married, non-pregnant, fecund women in 2006-07 were used. Logistic regression analysis was used to identify factors associated with the use of any contraceptive method and whether the influence of these factors changed between the survey years. Changes in the method mix were examined. The effects of urban/rural residence, wealth and education on contraceptive use changed between 1990-91 and 2006-07. Differentials in contraceptive use by residence, wealth and education declined and were accompanied by changes in the method mix. In rural areas and among less-educated women, the contribution of traditional methods to the method mix increased. Among the poorest women, the method mix shifted towards traditional methods and condoms. Less-educated, rural, Pakistani women increased the use of family planning at a faster rate than more-educated, urban, women by adopting the use of traditional family planning methods. Poor women also increased family planning use more quickly than non-poor women, by adopting condoms and traditional methods. The more rapid increase in the demand for family planning among poorer, less-educated, rural women is a positive trend. In order to convert this demand into the use of longer-term modern methods, however, access to high quality services must be improved in rural and low-income urban areas.

How far is mixed methods research in the field of health policy and systems in Africa? A scoping review.

PubMed

De Allegri, M; Sieleunou, I; Abiiro, G A; Ridde, V

2018-04-01

Both the academic and the policy community are calling for wider application of mixed methods research, suggesting that combined use of quantitative and qualitative methods is most suitable to assess and understand the complexities of health interventions. In spite of recent growth in mixed methods studies, limited efforts have been directed towards appraising and synthetizing to what extent and how mixed methods have been applied specifically to Health Policy and Systems Research (HPSR) in low- and middle-income countries (LMICs). We aimed at filling this gap in knowledge, by exploring the scope and quality of mixed methods research in the African context. We conducted a scoping review applying the framework developed by Arksey and O'Malley and modified by Levac et al. to identify and extract data from relevant studies published between 1950 and 2013. We limited our search to peer-reviewed HPSR publications in English, which combined at least one qualitative and one quantitative method and focused on Africa. Among the 105 studies that were retained for data extraction, over 60% were published after 2010. Nearly 50% of all studies addressed topics relevant to Health Systems, while Health Policy and Health Outcomes studies accounted respectively for 40% and 10% of all publications. The quality of the application of mixed methods varied greatly across studies, with a relatively small proportion of studies stating clearly defined research questions and differentiating quantitative and qualitative elements, including sample sizes and analytical approaches. The methodological weaknesses observed could be linked to the paucity of specific training opportunities available to people interested in applying mixed methods to HPSR in LMICs as well as to the limitations on word limit, scope and peer-review processes at the journals levels. Increasing training opportunities and enhancing journal flexibility may result in more and better quality mixed methods publications.

Use and misuse of mixed methods in population oral health research: A scoping review.

PubMed

Gupta, A; Keuskamp, D

2018-05-30

Despite the known benefits of a mixed methods approach in health research, little is known of its use in the field of population oral health. To map the extent of literature using a mixed methods approach to examine population oral health outcomes. For a comprehensive search of all the available literature published in the English language, databases including PubMed, Dentistry and Oral Sciences Source (DOSS), CINAHL, Web of Science and EMBASE (including Medline) were searched using a range of keywords from inception to October 2017. Only peer-reviewed, population-based studies of oral health outcomes conducted among non-institutionalised participants and using mixed methods were considered eligible for inclusion. Only nine studies met the inclusion criteria and were included in the review. The most frequent oral health outcome investigated was caries experience. However, most studies lacked a theoretical rationale or framework for using mixed methods, or supporting the use of qualitative data. Concurrent triangulation with a convergent design was the most commonly used mixed methods typology for integrating quantitative and qualitative data. The tools used to collect quantitative and qualitative data were mostly limited to surveys and interviews. With growing complexity recognised in the determinants of oral disease, future studies addressing population oral health outcomes are likely to benefit from the use of mixed methods. Explicit consideration of theoretical framework and methodology will strengthen those investigations. Copyright© 2018 Dennis Barber Ltd.

A mixed-methods approach to systematic reviews.

PubMed

Pearson, Alan; White, Heath; Bath-Hextall, Fiona; Salmond, Susan; Apostolo, Joao; Kirkpatrick, Pamela

2015-09-01

There are an increasing number of published single-method systematic reviews that focus on different types of evidence related to a particular topic. As policy makers and practitioners seek clear directions for decision-making from systematic reviews, it is likely that it will be increasingly difficult for them to identify 'what to do' if they are required to find and understand a plethora of syntheses related to a particular topic.Mixed-methods systematic reviews are designed to address this issue and have the potential to produce systematic reviews of direct relevance to policy makers and practitioners.On the basis of the recommendations of the Joanna Briggs Institute International Mixed Methods Reviews Methodology Group in 2012, the Institute adopted a segregated approach to mixed-methods synthesis as described by Sandelowski et al., which consists of separate syntheses of each component method of the review. Joanna Briggs Institute's mixed-methods synthesis of the findings of the separate syntheses uses a Bayesian approach to translate the findings of the initial quantitative synthesis into qualitative themes and pooling these with the findings of the initial qualitative synthesis.

Connecting the Dots and Merging Meaning: Using Mixed Methods to Study Primary Care Delivery Transformation

PubMed Central

Scammon, Debra L; Tomoaia-Cotisel, Andrada; Day, Rachel L; Day, Julie; Kim, Jaewhan; Waitzman, Norman J; Farrell, Timothy W; Magill, Michael K

2013-01-01

Objective. To demonstrate the value of mixed methods in the study of practice transformation and illustrate procedures for connecting methods and for merging findings to enhance the meaning derived. Data Source/Study Setting. An integrated network of university-owned, primary care practices at the University of Utah (Community Clinics or CCs). CC has adopted Care by Design, its version of the Patient Centered Medical Home. Study Design. Convergent case study mixed methods design. Data Collection/Extraction Methods. Analysis of archival documents, internal operational reports, in-clinic observations, chart audits, surveys, semistructured interviews, focus groups, Centers for Medicare and Medicaid Services database, and the Utah All Payer Claims Database. Principal Findings. Each data source enriched our understanding of the change process and understanding of reasons that certain changes were more difficult than others both in general and for particular clinics. Mixed methods enabled generation and testing of hypotheses about change and led to a comprehensive understanding of practice change. Conclusions. Mixed methods are useful in studying practice transformation. Challenges exist but can be overcome with careful planning and persistence. PMID:24279836

Concrete Mixing Methods and Concrete Mixers: State of the Art

PubMed Central

Ferraris, Chiara F.

2001-01-01

As for all materials, the performance of concrete is determined by its microstructure. Its microstructure is determined by its composition, its curing conditions, and also by the mixing method and mixer conditions used to process the concrete. This paper gives an overview of the various types of mixing methods and concrete mixers commercially available used by the concrete industry. There are two main types of mixers used: batch mixers and continuous mixers. Batch mixers are the most common. To determine the mixing method best suited for a specific application, factors to be considered include: location of the construction site (distance from the batching plant), the amount of concrete needed, the construction schedule (volume of concrete needed per hour), and the cost. Ultimately, the quality of the concrete produced determines its performance after placement. An important measure of the quality is the homogeneity of the material after mixing. This paper will review mixing methods in regards to the quality of the concrete produced. Some procedures used to determine the effectiveness of the mixing will be examined. PMID:27500029

Achieving Integration in Mixed Methods Designs—Principles and Practices

PubMed Central

Fetters, Michael D; Curry, Leslie A; Creswell, John W

2013-01-01

Mixed methods research offers powerful tools for investigating complex processes and systems in health and health care. This article describes integration principles and practices at three levels in mixed methods research and provides illustrative examples. Integration at the study design level occurs through three basic mixed method designs—exploratory sequential, explanatory sequential, and convergent—and through four advanced frameworks—multistage, intervention, case study, and participatory. Integration at the methods level occurs through four approaches. In connecting, one database links to the other through sampling. With building, one database informs the data collection approach of the other. When merging, the two databases are brought together for analysis. With embedding, data collection and analysis link at multiple points. Integration at the interpretation and reporting level occurs through narrative, data transformation, and joint display. The fit of integration describes the extent the qualitative and quantitative findings cohere. Understanding these principles and practices of integration can help health services researchers leverage the strengths of mixed methods. PMID:24279835

Achieving integration in mixed methods designs-principles and practices.

PubMed

Fetters, Michael D; Curry, Leslie A; Creswell, John W

2013-12-01

Mixed methods research offers powerful tools for investigating complex processes and systems in health and health care. This article describes integration principles and practices at three levels in mixed methods research and provides illustrative examples. Integration at the study design level occurs through three basic mixed method designs-exploratory sequential, explanatory sequential, and convergent-and through four advanced frameworks-multistage, intervention, case study, and participatory. Integration at the methods level occurs through four approaches. In connecting, one database links to the other through sampling. With building, one database informs the data collection approach of the other. When merging, the two databases are brought together for analysis. With embedding, data collection and analysis link at multiple points. Integration at the interpretation and reporting level occurs through narrative, data transformation, and joint display. The fit of integration describes the extent the qualitative and quantitative findings cohere. Understanding these principles and practices of integration can help health services researchers leverage the strengths of mixed methods. © Health Research and Educational Trust.

Analysis of baseline, average, and longitudinally measured blood pressure data using linear mixed models.

PubMed

Hossain, Ahmed; Beyene, Joseph

2014-01-01

This article compares baseline, average, and longitudinal data analysis methods for identifying genetic variants in genome-wide association study using the Genetic Analysis Workshop 18 data. We apply methods that include (a) linear mixed models with baseline measures, (b) random intercept linear mixed models with mean measures outcome, and (c) random intercept linear mixed models with longitudinal measurements. In the linear mixed models, covariates are included as fixed effects, whereas relatedness among individuals is incorporated as the variance-covariance structure of the random effect for the individuals. The overall strategy of applying linear mixed models decorrelate the data is based on Aulchenko et al.'s GRAMMAR. By analyzing systolic and diastolic blood pressure, which are used separately as outcomes, we compare the 3 methods in identifying a known genetic variant that is associated with blood pressure from chromosome 3 and simulated phenotype data. We also analyze the real phenotype data to illustrate the methods. We conclude that the linear mixed model with longitudinal measurements of diastolic blood pressure is the most accurate at identifying the known single-nucleotide polymorphism among the methods, but linear mixed models with baseline measures perform best with systolic blood pressure as the outcome.

Mixing Research Methods in Health Professional Degrees: Thoughts for Undergraduate Students and Supervisors

ERIC Educational Resources Information Center

Anaf, Sophie; Sheppard, Lorraine A.

2007-01-01

This commentary considers some of the challenges of applying mixed methods research in undergraduate research degrees, especially in professions with a clinical health focus. Our experience in physiotherapy academia is used as an example. Mixed methods research is increasingly appreciated in its own right as a "third paradigm," however the success…

Using Mixed Methods to Analyze Video Data: A Mathematics Teacher Professional Development Example

ERIC Educational Resources Information Center

DeCuir-Gunby, Jessica T.; Marshall, Patricia L.; McCulloch, Allison W.

2012-01-01

This article uses data from 65 teachers participating in a K-2 mathematics professional development research project as an example of how to analyze video recordings of teachers' classroom lessons using mixed methods. Through their discussion, the authors demonstrate how using a mixed methods approach to classroom video analysis allows researchers…

Use of the Transformative Framework in Mixed Methods Studies

ERIC Educational Resources Information Center

Sweetman, David; Badiee, Manijeh; Creswell, John W.

2010-01-01

A concern exists that mixed methods studies do not contain advocacy stances. Preliminary evidence suggests that this is not the case, but to address this issue in more depth the authors examined 13 mixed methods studies that contained an advocacy, transformative lens. Such a lens consisted of incorporating intent to advocate for an improvement in…

Internet-Mediated Technologies and Mixed Methods Research: Problems and Prospects

ERIC Educational Resources Information Center

Hesse-Biber, Sharlene; Griffin, Amy J.

2013-01-01

This article provides an examination of a range of mixed methods research projects that employ Internet-mediated technologies (IMT) for data collection. Using a case study approach, this article allows for the uncovering of a process by which IMT are used as a data collection medium in mixed methods praxis. Under the theoretical position of medium…

A Mixed Methods Investigation of Mixed Methods Sampling Designs in Social and Health Science Research

ERIC Educational Resources Information Center

Collins, Kathleen M. T.; Onwuegbuzie, Anthony J.; Jiao, Qun G.

2007-01-01

A sequential design utilizing identical samples was used to classify mixed methods studies via a two-dimensional model, wherein sampling designs were grouped according to the time orientation of each study's components and the relationship of the qualitative and quantitative samples. A quantitative analysis of 121 studies representing nine fields…

Benefits, Challenges, and Dynamism of Positionalities Associated with Mixed Methods Research in Developing Countries: Evidence from Ghana

ERIC Educational Resources Information Center

Teye, Joseph Kofi

2012-01-01

Although mixed methods designs have gained visibility in recent years, most of the publications on this methodological strategy have been written by scholars in the developed world. Consequently, the practical challenges associated with mixed methods research in developing countries have not been adequately discussed in the literature. Relying on…

Cognitive Task Complexity Effects on L2 Writing Performance: An Application of Mixed-Methods Approaches

ERIC Educational Resources Information Center

Abdi Tabari, Mahmoud; Ivey, Toni A.

2015-01-01

This paper provides a methodological review of previous research on cognitive task complexity, since the term emerged in 1995, and investigates why much research was more quantitative rather than qualitative. Moreover, it sheds light onto the studies which used the mixed-methods approach and determines which version of the mixed-methods designs…

Grounded Theory in Practice: Is It Inherently a Mixed Method?

ERIC Educational Resources Information Center

Johnson, R. B.; McGowan, M. W.; Turner, L. A.

2010-01-01

We address 2 key points of contention in this article. First, we engage the debate concerning whether particular methods are necessarily linked to particular research paradigms. Second, we briefly describe a mixed methods version of grounded theory (MM-GT). Grounded theory can be tailored to work well in any of the 3 major forms of mixed methods…

Researching reducing health disparities: mixed-methods approaches.

PubMed

Stewart, Miriam; Makwarimba, Edward; Barnfather, Alison; Letourneau, Nicole; Neufeld, Anne

2008-03-01

There is a pressing need for assessment and intervention research focused on reducing health disparities. In our research program, the use of mixed methods has enhanced assessment of the mediating impacts of social support on the health of vulnerable populations and enabled the design and testing of support interventions. This paper highlights the benefits and challenges of mixed methods for investigating inequities; and, illustrates the application of mixed methods in two exemplar studies focused on vulnerable populations in Canada. Qualitative methods fostered in-depth understanding of vulnerable populations' support needs, support resources, intervention preferences, and satisfaction with intervention strategies and impacts. Quantitative methods documented the effectiveness and outcomes of intervention strategies, and enhanced the reliability and validity of assessments and interventions. The researchers demonstrate that participatory strategies are needed to make studies more relevant to reducing health disparities, contextually appropriate, and empowering.

Mixed methods research: a design for emergency care research?

PubMed

Cooper, Simon; Porter, Jo; Endacott, Ruth

2011-08-01

This paper follows previous publications on generic qualitative approaches, qualitative designs and action research in emergency care by this group of authors. Contemporary views on mixed methods approaches are considered, with a particular focus on the design choice and the amalgamation of qualitative and quantitative data emphasising the timing of data collection for each approach, their relative 'weight' and how they will be mixed. Mixed methods studies in emergency care are reviewed before the variety of methodological approaches and best practice considerations are presented. The use of mixed methods in clinical studies is increasing, aiming to answer questions such as 'how many' and 'why' in the same study, and as such are an important and useful approach to many key questions in emergency care.

Understanding the value of mixed methods research: the Children's Safety Initiative-Emergency Medical Services.

PubMed

Hansen, Matthew; O'Brien, Kerth; Meckler, Garth; Chang, Anna Marie; Guise, Jeanne-Marie

2016-07-01

Mixed methods research has significant potential to broaden the scope of emergency care and specifically emergency medical services investigation. Mixed methods studies involve the coordinated use of qualitative and quantitative research approaches to gain a fuller understanding of practice. By combining what is learnt from multiple methods, these approaches can help to characterise complex healthcare systems, identify the mechanisms of complex problems such as medical errors and understand aspects of human interaction such as communication, behaviour and team performance. Mixed methods approaches may be particularly useful for out-of-hospital care researchers because care is provided in complex systems where equipment, interpersonal interactions, societal norms, environment and other factors influence patient outcomes. The overall objectives of this paper are to (1) introduce the fundamental concepts and approaches of mixed methods research and (2) describe the interrelation and complementary features of the quantitative and qualitative components of mixed methods studies using specific examples from the Children's Safety Initiative-Emergency Medical Services (CSI-EMS), a large National Institutes of Health-funded research project conducted in the USA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Methods That Matter: Integrating Mixed Methods for More Effective Social Science Research

ERIC Educational Resources Information Center

Hay, M. Cameron, Ed.

2016-01-01

To do research that really makes a difference--the authors of this book argue--social scientists need questions and methods that reflect the complexity of the world. Bringing together a consortium of voices across a variety of fields, "Methods that Matter" offers compelling and successful examples of mixed methods research that do just…

Improved accuracy for finite element structural analysis via an integrated force method

NASA Technical Reports Server (NTRS)

Patnaik, S. N.; Hopkins, D. A.; Aiello, R. A.; Berke, L.

1992-01-01

A comparative study was carried out to determine the accuracy of finite element analyses based on the stiffness method, a mixed method, and the new integrated force and dual integrated force methods. The numerical results were obtained with the following software: MSC/NASTRAN and ASKA for the stiffness method; an MHOST implementation method for the mixed method; and GIFT for the integrated force methods. The results indicate that on an overall basis, the stiffness and mixed methods present some limitations. The stiffness method generally requires a large number of elements in the model to achieve acceptable accuracy. The MHOST method tends to achieve a higher degree of accuracy for course models than does the stiffness method implemented by MSC/NASTRAN and ASKA. The two integrated force methods, which bestow simultaneous emphasis on stress equilibrium and strain compatibility, yield accurate solutions with fewer elements in a model. The full potential of these new integrated force methods remains largely unexploited, and they hold the promise of spawning new finite element structural analysis tools.

Paradigms, pragmatism and possibilities: mixed-methods research in speech and language therapy.

PubMed

Glogowska, Margaret

2011-01-01

After the decades of the so-called 'paradigm wars' in social science research methodology and the controversy about the relative place and value of quantitative and qualitative research methodologies, 'paradigm peace' appears to have now been declared. This has come about as many researchers have begun to take a 'pragmatic' approach in the selection of research methodology, choosing the methodology best suited to answering the research question rather than conforming to a methodological orthodoxy. With the differences in the philosophical underpinnings of the two traditions set to one side, an increasing awareness, and valuing, of the 'mixed-methods' approach to research is now present in the fields of social, educational and health research. To explore what is meant by mixed-methods research and the ways in which quantitative and qualitative methodologies and methods can be combined and integrated, particularly in the broad field of health services research and the narrower one of speech and language therapy. The paper discusses the ways in which methodological approaches have already been combined and integrated in health services research and speech and language therapy, highlighting the suitability of mixed-methods research for answering the typically multifaceted questions arising from the provision of complex interventions. The challenges of combining and integrating quantitative and qualitative methods and the barriers to the adoption of mixed-methods approaches are also considered. The questions about healthcare, as it is being provided in the 21st century, calls for a range of methodological approaches. This is particularly the case for human communication and its disorders, where mixed-methods research offers a wealth of possibilities. In turn, speech and language therapy research should be able to contribute substantively to the future development of mixed-methods research. © 2010 Royal College of Speech & Language Therapists.

An Introductory Mixed-Methods Intersectionality Analysis of College Access and Equity: An Examination of First-Generation Asian Americans and Pacific Islanders

ERIC Educational Resources Information Center

Museus, Samuel D.

2011-01-01

In this article, the author discusses how researchers can use mixed-methods approaches and intersectional analyses to understand college access among first-generation Asian American and Pacific Islanders (AAPIs). First, he discusses the utility of mixed-methods approaches and intersectionality research in studying college access. Then, he…

A Systematic Review of Mixed Methods Research on Human Factors and Ergonomics in Health Care

PubMed Central

Carayon, Pascale; Kianfar, Sarah; Li, Yaqiong; Xie, Anping; Alyousef, Bashar; Wooldridge, Abigail

2016-01-01

This systematic literature review provides information on the use of mixed methods research in human factors and ergonomics (HFE) research in health care. Using the PRISMA methodology, we searched four databases (PubMed, PsycInfo, Web of Science, and Engineering Village) for studies that met the following inclusion criteria: (1) field study in health care, (2) mixing of qualitative and quantitative data, (3) HFE issues, and (4) empirical evidence. Using an iterative and collaborative process supported by a structured data collection form, the six authors identified a total of 58 studies that primarily address HFE issues in health information technology (e.g., usability) and in the work of healthcare workers. About two-thirds of the mixed methods studies used the convergent parallel study design where quantitative and qualitative data were collected simultaneously. A variety of methods were used for collecting data, including interview, survey and observation. The most frequent combination involved interview for qualitative data and survey for quantitative data. The use of mixed methods in healthcare HFE research has increased over time. However, increasing attention should be paid to the formal literature on mixed methods research to enhance the depth and breadth of this research. PMID:26154228

Adjusting case mix payment amounts for inaccurately reported comorbidity data.

PubMed

Sutherland, Jason M; Hamm, Jeremy; Hatcher, Jeff

2010-03-01

Case mix methods such as diagnosis related groups have become a basis of payment for inpatient hospitalizations in many countries. Specifying cost weight values for case mix system payment has important consequences; recent evidence suggests case mix cost weight inaccuracies influence the supply of some hospital-based services. To begin to address the question of case mix cost weight accuracy, this paper is motivated by the objective of improving the accuracy of cost weight values due to inaccurate or incomplete comorbidity data. The methods are suitable to case mix methods that incorporate disease severity or comorbidity adjustments. The methods are based on the availability of detailed clinical and cost information linked at the patient level and leverage recent results from clinical data audits. A Bayesian framework is used to synthesize clinical data audit information regarding misclassification probabilities into cost weight value calculations. The models are implemented through Markov chain Monte Carlo methods. An example used to demonstrate the methods finds that inaccurate comorbidity data affects cost weight values by biasing cost weight values (and payments) downward. The implications for hospital payments are discussed and the generalizability of the approach is explored.

More than Method?: A Discussion of Paradigm Differences within Mixed Methods Research

ERIC Educational Resources Information Center

Harrits, Gitte Sommer

2011-01-01

This article challenges the idea that mixed methods research (MMR) constitutes a coherent research paradigm and explores how different research paradigms exist within MMR. Tracing paradigmatic differences at the level of methods, ontology, and epistemology, two MMR strategies are discussed: nested analysis, recently presented by the American…

Method of chaotic mixing and improved stirred tank reactors

DOEpatents

Muzzio, F.J.; Lamberto, D.J.

1999-07-13

The invention provides a method and apparatus for efficiently achieving a homogeneous mixture of fluid components by introducing said components having a Reynolds number of between about [le]1 to about 500 into a vessel and continuously perturbing the mixing flow by altering the flow speed and mixing time until homogeneity is reached. This method prevents the components from aggregating into non-homogeneous segregated regions within said vessel during mixing and substantially reduces the time the admixed components reach homogeneity. 19 figs.

Method of chaotic mixing and improved stirred tank reactors

DOEpatents

Muzzio, Fernando J.; Lamberto, David J.

1999-01-01

The invention provides a method and apparatus for efficiently achieving a homogeneous mixture of fluid components by introducing said components having a Reynolds number of between about .ltoreq.1 to about 500 into a vessel and continuously perturbing the mixing flow by altering the flow speed and mixing time until homogeniety is reached. This method prevents the components from aggregating into non-homogeneous segregated regions within said vessel during mixing and substantially reduces the time the admixed components reach homogeneity.

The effect of mixing method on tricalcium silicate-based cement.

PubMed

Duque, J A; Fernandes, S L; Bubola, J P; Duarte, M A H; Camilleri, J; Marciano, M A

2018-01-01

To evaluate the effect of three methods of mixing on the physical and chemical properties of tricalcium silicate-based cements. The materials evaluated were MTA Angelus and Portland cement with 20% zirconium oxide (PC-20-Zr). The cements were mixed using a 3 : 1 powder-to-liquid ratio. The mixing methods were manual (m), trituration (tr) and ultrasonic (us) activation. The materials were characterized by means of scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy. Flowability was analysed according to ANSI/ADA 57/2012. Initial and final setting times were assessed following ASTM C266/08. Volume change was evaluated using a micro-CT volumetric method. Solubility was analysed according to ADA 57/2012. pH and calcium ion release were measured after 3, 24, 72 and 168 h. Statistical analysis was performed using two-way analysis of variance. The level of significance was set at P = 0.05. The SEM analysis revealed that ultrasonic activation was associated with a homogeneous distribution of particles. Flowability, volume change and initial setting time were not influenced by the mixing method (P > 0.05). Solubility was influenced by the mixing method (P < 0.05). For pH, at 168 h, significant differences were found between MTA-m and PC-20-Zr-m (P < 0.05). For calcium ion release, PC-20-Zr-tr had higher values than MTA-m at 3 h, and MTA-tr had higher values than PC-20-Zr-m at 168 h (P < 0.05). The ultrasonic and trituration methods led to higher calcium ion release and pH compared with manual mixing for all cements, whilst the ultrasonic method produced smaller particles for the PC-20-Zr cement. Flow, setting times and volume change were not influenced by the mixing method used; however, it did have an impact on solubility. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Method of forming nanodielectrics

DOEpatents

Tuncer, Enis [Knoxville, TN; Polyzos, Georgios [Oak Ridge, TN

2014-01-07

A method of making a nanoparticle filled dielectric material. The method includes mixing nanoparticle precursors with a polymer material and reacting the nanoparticle mixed with the polymer material to form nanoparticles dispersed within the polymer material to form a dielectric composite.

A survey of mixed finite element methods

NASA Technical Reports Server (NTRS)

Brezzi, F.

1987-01-01

This paper is an introduction to and an overview of mixed finite element methods. It discusses the mixed formulation of certain basic problems in elasticity and hydrodynamics. It also discusses special techniques for solving the discrete problem.

Mixed methods research design for pragmatic psychoanalytic studies.

PubMed

Tillman, Jane G; Clemence, A Jill; Stevens, Jennifer L

2011-10-01

Calls for more rigorous psychoanalytic studies have increased over the past decade. The field has been divided by those who assert that psychoanalysis is properly a hermeneutic endeavor and those who see it as a science. A comparable debate is found in research methodology, where qualitative and quantitative methods have often been seen as occupying orthogonal positions. Recently, Mixed Methods Research (MMR) has emerged as a viable "third community" of research, pursuing a pragmatic approach to research endeavors through integrating qualitative and quantitative procedures in a single study design. Mixed Methods Research designs and the terminology associated with this emerging approach are explained, after which the methodology is explored as a potential integrative approach to a psychoanalytic human science. Both qualitative and quantitative research methods are reviewed, as well as how they may be used in Mixed Methods Research to study complex human phenomena.

Qualitative and mixed methods research in dissemination and implementation science: introduction to the special issue.

PubMed

Southam-Gerow, Michael A; Dorsey, Shannon

2014-01-01

This special issue provides examples of how qualitative and mixed methods research approaches can be used in dissemination and implementation science. In this introductory article, we provide a brief rationale for why and how qualitative and mixed methods approaches can be useful in moving the field forward. Specifically, we provide a brief primer on common qualitative methods, including a review of guidelines provided by the National Institutes of Health. Next, we introduce the six articles in the issue. The first of the articles by Palinkas represents a more thorough and authoritative discussion related to qualitative methods, using the other five articles in the issue (and other published works) as examples. The remaining five articles are empirical and/or descriptive articles of recently completed or ongoing qualitative or mixed methods studies related to dissemination and implementation of evidence-based practices for children and adolescents.

Extending existing structural identifiability analysis methods to mixed-effects models.

PubMed

Janzén, David L I; Jirstrand, Mats; Chappell, Michael J; Evans, Neil D

2018-01-01

The concept of structural identifiability for state-space models is expanded to cover mixed-effects state-space models. Two methods applicable for the analytical study of the structural identifiability of mixed-effects models are presented. The two methods are based on previously established techniques for non-mixed-effects models; namely the Taylor series expansion and the input-output form approach. By generating an exhaustive summary, and by assuming an infinite number of subjects, functions of random variables can be derived which in turn determine the distribution of the system's observation function(s). By considering the uniqueness of the analytical statistical moments of the derived functions of the random variables, the structural identifiability of the corresponding mixed-effects model can be determined. The two methods are applied to a set of examples of mixed-effects models to illustrate how they work in practice. Copyright © 2017 Elsevier Inc. All rights reserved.

A Modularity-Based Method Reveals Mixed Modules from Chemical-Gene Heterogeneous Network

PubMed Central

Song, Jianglong; Tang, Shihuan; Liu, Xi; Gao, Yibo; Yang, Hongjun; Lu, Peng

2015-01-01

For a multicomponent therapy, molecular network is essential to uncover its specific mode of action from a holistic perspective. The molecular system of a Traditional Chinese Medicine (TCM) formula can be represented by a 2-class heterogeneous network (2-HN), which typically includes chemical similarities, chemical-target interactions and gene interactions. An important premise of uncovering the molecular mechanism is to identify mixed modules from complex chemical-gene heterogeneous network of a TCM formula. We thus proposed a novel method (MixMod) based on mixed modularity to detect accurate mixed modules from 2-HNs. At first, we compared MixMod with Clauset-Newman-Moore algorithm (CNM), Markov Cluster algorithm (MCL), Infomap and Louvain on benchmark 2-HNs with known module structure. Results showed that MixMod was superior to other methods when 2-HNs had promiscuous module structure. Then these methods were tested on a real drug-target network, in which 88 disease clusters were regarded as real modules. MixMod could identify the most accurate mixed modules from the drug-target 2-HN (normalized mutual information 0.62 and classification accuracy 0.4524). In the end, MixMod was applied to the 2-HN of Buchang naoxintong capsule (BNC) and detected 49 mixed modules. By using enrichment analysis, we investigated five mixed modules that contained primary constituents of BNC intestinal absorption liquid. As a matter of fact, the findings of in vitro experiments using BNC intestinal absorption liquid were found to highly accord with previous analysis. Therefore, MixMod is an effective method to detect accurate mixed modules from chemical-gene heterogeneous networks and further uncover the molecular mechanism of multicomponent therapies, especially TCM formulae. PMID:25927435

Revisiting the Quantitative-Qualitative Debate: Implications for Mixed-Methods Research

PubMed Central

SALE, JOANNA E. M.; LOHFELD, LYNNE H.; BRAZIL, KEVIN

2015-01-01

Health care research includes many studies that combine quantitative and qualitative methods. In this paper, we revisit the quantitative-qualitative debate and review the arguments for and against using mixed-methods. In addition, we discuss the implications stemming from our view, that the paradigms upon which the methods are based have a different view of reality and therefore a different view of the phenomenon under study. Because the two paradigms do not study the same phenomena, quantitative and qualitative methods cannot be combined for cross-validation or triangulation purposes. However, they can be combined for complementary purposes. Future standards for mixed-methods research should clearly reflect this recommendation. PMID:26523073

Parents' Reasons for Choosing Non-Public Non-Denominational Elementary Schools for Low Socioeconomic Students in Alabama: A Mixed-Methods Study

ERIC Educational Resources Information Center

Francis-Thomas, Kyle

2016-01-01

The purpose of this mixed-methods study was to determine parents' reasons for choosing Non-Public Non-Denominational Elementary Schools for low socioeconomic students in Alabama. Low socioeconomic students were defined as students who qualified for free/reduced lunches. The research was designed as a mixed methods study with data being collected…

The Contribution of Mixed Methods Research to the Field of Childhood Trauma: A Narrative Review Focused on Data Integration

ERIC Educational Resources Information Center

Boeije, Hennie; Slagt, Meike; van Wesel, Floryt

2013-01-01

In mixed methods research (MMR), integrating the quantitative and the qualitative components of a study is assumed to result in additional knowledge (or "yield"). This narrative review examines the extent to which MMR is used in the field of childhood trauma and provides directions for improving mixed methods studies in this field. A…

Reconciling incongruous qualitative and quantitative findings in mixed methods research: exemplars from research with drug using populations.

PubMed

Wagner, Karla D; Davidson, Peter J; Pollini, Robin A; Strathdee, Steffanie A; Washburn, Rachel; Palinkas, Lawrence A

2012-01-01

Mixed methods research is increasingly being promoted in the health sciences as a way to gain more comprehensive understandings of how social processes and individual behaviours shape human health. Mixed methods research most commonly combines qualitative and quantitative data collection and analysis strategies. Often, integrating findings from multiple methods is assumed to confirm or validate the findings from one method with the findings from another, seeking convergence or agreement between methods. Cases in which findings from different methods are congruous are generally thought of as ideal, whilst conflicting findings may, at first glance, appear problematic. However, the latter situation provides the opportunity for a process through which apparently discordant results are reconciled, potentially leading to new emergent understandings of complex social phenomena. This paper presents three case studies drawn from the authors' research on HIV risk amongst injection drug users in which mixed methods studies yielded apparently discrepant results. We use these case studies (involving injection drug users [IDUs] using a Needle/Syringe Exchange Program in Los Angeles, CA, USA; IDUs seeking to purchase needle/syringes at pharmacies in Tijuana, Mexico; and young street-based IDUs in San Francisco, CA, USA) to identify challenges associated with integrating findings from mixed methods projects, summarize lessons learned, and make recommendations for how to more successfully anticipate and manage the integration of findings. Despite the challenges inherent in reconciling apparently conflicting findings from qualitative and quantitative approaches, in keeping with others who have argued in favour of integrating mixed methods findings, we contend that such an undertaking has the potential to yield benefits that emerge only through the struggle to reconcile discrepant results and may provide a sum that is greater than the individual qualitative and quantitative parts. Copyright © 2011 Elsevier B.V. All rights reserved.

Reconciling incongruous qualitative and quantitative findings in mixed methods research: exemplars from research with drug using populations

PubMed Central

Wagner, Karla D.; Davidson, Peter J.; Pollini, Robin A.; Strathdee, Steffanie A.; Washburn, Rachel; Palinkas, Lawrence A.

2011-01-01

Mixed methods research is increasingly being promoted in the health sciences as a way to gain more comprehensive understandings of how social processes and individual behaviours shape human health. Mixed methods research most commonly combines qualitative and quantitative data collection and analysis strategies. Often, integrating findings from multiple methods is assumed to confirm or validate the findings from one method with the findings from another, seeking convergence or agreement between methods. Cases in which findings from different methods are congruous are generally thought of as ideal, while conflicting findings may, at first glance, appear problematic. However, the latter situation provides the opportunity for a process through which apparently discordant results are reconciled, potentially leading to new emergent understandings of complex social phenomena. This paper presents three case studies drawn from the authors’ research on HIV risk among injection drug users in which mixed methods studies yielded apparently discrepant results. We use these case studies (involving injection drug users [IDUs] using a needle/syringe exchange program in Los Angeles, California, USA; IDUs seeking to purchase needle/syringes at pharmacies in Tijuana, Mexico; and young street-based IDUs in San Francisco, CA, USA) to identify challenges associated with integrating findings from mixed methods projects, summarize lessons learned, and make recommendations for how to more successfully anticipate and manage the integration of findings. Despite the challenges inherent in reconciling apparently conflicting findings from qualitative and quantitative approaches, in keeping with others who have argued in favour of integrating mixed methods findings, we contend that such an undertaking has the potential to yield benefits that emerge only through the struggle to reconcile discrepant results and may provide a sum that is greater than the individual qualitative and quantitative parts. PMID:21680168

Updating and testing of a Finnish method for mixed municipal solid waste composition studies.

PubMed

Liikanen, M; Sahimaa, O; Hupponen, M; Havukainen, J; Sorvari, J; Horttanainen, M

2016-06-01

More efficient recycling of municipal solid waste (MSW) is an essential precondition for turning Europe into a circular economy. Thus, the recycling of MSW must increase significantly in several member states, including Finland. This has increased the interest in the composition of mixed MSW. Due to increased information needs, a method for mixed MSW composition studies was introduced in Finland in order to improve the national comparability of composition study results. The aim of this study was to further develop the method so that it corresponds to the information needed about the composition of mixed MSW and still works in practice. A survey and two mixed MSW composition studies were carried out in the study. According to the responses of the survey, the intensification of recycling, the landfill ban on organic waste and the producer responsibility for packaging waste have particularly influenced the need for information about the composition of mixed MSW. The share of biowaste in mixed MSW interested the respondents most. Additionally, biowaste proved to be the largest waste fraction in mixed MSW in the composition studies. It constituted over 40% of mixed MSW in both composition studies. For these reasons, the classification system of the method was updated by further defining the classifications of biowaste. The classifications of paper as well as paperboard and cardboard were also updated. The updated classification system provides more information on the share of avoidable food waste and waste materials suitable for recycling in mixed MSW. The updated method and the information gained from the composition studies are important in ensuring that the method will be adopted by municipal waste management companies and thus used widely in Finland. Copyright © 2016 Elsevier Ltd. All rights reserved.

Deep Whole-Genome Sequencing to Detect Mixed Infection of Mycobacterium tuberculosis

PubMed Central

Gan, Mingyu; Liu, Qingyun; Yang, Chongguang; Gao, Qian; Luo, Tao

2016-01-01

Mixed infection by multiple Mycobacterium tuberculosis (MTB) strains is associated with poor treatment outcome of tuberculosis (TB). Traditional genotyping methods have been used to detect mixed infections of MTB, however, their sensitivity and resolution are limited. Deep whole-genome sequencing (WGS) has been proved highly sensitive and discriminative for studying population heterogeneity of MTB. Here, we developed a phylogenetic-based method to detect MTB mixed infections using WGS data. We collected published WGS data of 782 global MTB strains from public database. We called homogeneous and heterogeneous single nucleotide variations (SNVs) of individual strains by mapping short reads to the ancestral MTB reference genome. We constructed a phylogenomic database based on 68,639 homogeneous SNVs of 652 MTB strains. Mixed infections were determined if multiple evolutionary paths were identified by mapping the SNVs of individual samples to the phylogenomic database. By simulation, our method could specifically detect mixed infections when the sequencing depth of minor strains was as low as 1× coverage, and when the genomic distance of two mixed strains was as small as 16 SNVs. By applying our methods to all 782 samples, we detected 47 mixed infections and 45 of them were caused by locally endemic strains. The results indicate that our method is highly sensitive and discriminative for identifying mixed infections from deep WGS data of MTB isolates. PMID:27391214

Intravenous Fluid Mixing in Normal Gravity, Partial Gravity, and Microgravity: Down-Selection of Mixing Methods

NASA Technical Reports Server (NTRS)

Niederhaus, Charles E.; Miller, Fletcher J.

2008-01-01

The missions envisioned under the Vision for Space Exploration will require development of new methods to handle crew medical care. Medications and intravenous (IV) fluids have been identified as one area needing development. Storing certain medications and solutions as powders or concentrates can both increase the shelf life and reduce the overall mass and volume of medical supplies. The powders or concentrates would then be mixed in an IV bag with Sterile Water for Injection produced in situ from the potable water supply. Fluid handling in microgravity is different than terrestrial settings, and requires special consideration in the design of equipment. This document describes the analyses and down-select activities used to identify the IV mixing method to be developed that is suitable for ISS and exploration missions. The chosen method is compatible with both normal gravity and microgravity, maintains sterility of the solution, and has low mass and power requirements. The method will undergo further development, including reduced gravity aircraft experiments and computations, in order to fully develop the mixing method and associated operational parameters.

Connecting the dots and merging meaning: using mixed methods to study primary care delivery transformation.

PubMed

Scammon, Debra L; Tomoaia-Cotisel, Andrada; Day, Rachel L; Day, Julie; Kim, Jaewhan; Waitzman, Norman J; Farrell, Timothy W; Magill, Michael K

2013-12-01

To demonstrate the value of mixed methods in the study of practice transformation and illustrate procedures for connecting methods and for merging findings to enhance the meaning derived. An integrated network of university-owned, primary care practices at the University of Utah (Community Clinics or CCs). CC has adopted Care by Design, its version of the Patient Centered Medical Home. Convergent case study mixed methods design. Analysis of archival documents, internal operational reports, in-clinic observations, chart audits, surveys, semistructured interviews, focus groups, Centers for Medicare and Medicaid Services database, and the Utah All Payer Claims Database. Each data source enriched our understanding of the change process and understanding of reasons that certain changes were more difficult than others both in general and for particular clinics. Mixed methods enabled generation and testing of hypotheses about change and led to a comprehensive understanding of practice change. Mixed methods are useful in studying practice transformation. Challenges exist but can be overcome with careful planning and persistence. © Health Research and Educational Trust.

Creating and Supporting a Mixed Methods Health Services Research Team

PubMed Central

Bowers, Barbara; Cohen, Lauren W; Elliot, Amy E; Grabowski, David C; Fishman, Nancy W; Sharkey, Siobhan S; Zimmerman, Sheryl; Horn, Susan D; Kemper, Peter

2013-01-01

Objective. To use the experience from a health services research evaluation to provide guidance in team development for mixed methods research. Methods. The Research Initiative Valuing Eldercare (THRIVE) team was organized by the Robert Wood Johnson Foundation to evaluate The Green House nursing home culture change program. This article describes the development of the research team and provides insights into how funders might engage with mixed methods research teams to maximize the value of the team. Results. Like many mixed methods collaborations, the THRIVE team consisted of researchers from diverse disciplines, embracing diverse methodologies, and operating under a framework of nonhierarchical, shared leadership that required new collaborations, engagement, and commitment in the context of finite resources. Strategies to overcome these potential obstacles and achieve success included implementation of a Coordinating Center, dedicated time for planning and collaborating across researchers and methodologies, funded support for in-person meetings, and creative optimization of resources. Conclusions. Challenges are inevitably present in the formation and operation of effective mixed methods research teams. However, funders and research teams can implement strategies to promote success. PMID:24138774

Factors Influencing Achievement in Undergraduate Social Science Research Methods Courses: A Mixed Methods Analysis

ERIC Educational Resources Information Center

Markle, Gail

2017-01-01

Undergraduate social science research methods courses tend to have higher than average rates of failure and withdrawal. Lack of success in these courses impedes students' progression through their degree programs and negatively impacts institutional retention and graduation rates. Grounded in adult learning theory, this mixed methods study…

Guidance for using mixed methods design in nursing practice research.

PubMed

Chiang-Hanisko, Lenny; Newman, David; Dyess, Susan; Piyakong, Duangporn; Liehr, Patricia

2016-08-01

The mixed methods approach purposefully combines both quantitative and qualitative techniques, enabling a multi-faceted understanding of nursing phenomena. The purpose of this article is to introduce three mixed methods designs (parallel; sequential; conversion) and highlight interpretive processes that occur with the synthesis of qualitative and quantitative findings. Real world examples of research studies conducted by the authors will demonstrate the processes leading to the merger of data. The examples include: research questions; data collection procedures and analysis with a focus on synthesizing findings. Based on experience with mixed methods studied, the authors introduce two synthesis patterns (complementary; contrasting), considering application for practice and implications for research. Copyright © 2015 Elsevier Inc. All rights reserved.

The effect of B{sub 2}O{sub 3} flux on growth NLBCO superconductor by solid state reaction and wet-mixing methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suharta, W. G., E-mail: wgsuharta@gmail.com; Wendri, N.; Ratini, N.

The synthesis of B{sub 2}O{sub 3} flux substituted NLBCO superconductor NdBa{sub 1.75}La{sub 0.25}Cu{sub 3}O{sub 7-∂} has been done using solid state reaction and wet-mixing methods in order to obtain homogeneous crystals and single phase. From DTA/TGA characteritations showed the synthesis process by wet-mixing requires a lower temperature than the solid state reaction in growing the superconductor NdBa{sub 1.75}La{sub 0.25}Cu{sub 3}O{sub 7-∂}. Therefore, in this research NdBa{sub 1.75}La{sub 0.25}Cu{sub 3}O{sub 7-∂} sample calcinated at 650°C for wet-mixing method and 820°C for solid state reaction methods. The all samples was sintered at 950°C for ten hours. Crystallinity of the sample was confirmedmore » using X-ray techniques and generally obtained sharp peaks that indicates the sample already well crystallized. Search match analyses for diffraction data gave weight fractions of impurity phase of the solid state reaction method higher than wet-mixing method. In this research showed decreasing the price of the lattice parameter about 1% with the addition of B{sub 2}O{sub 3} flux for the both synthesis process and 2% of wet mixing process for all samples. Characterization using scanning electron microscopy (SEM) showed the distribution of crystal zise for wet-mixing method more homogeneous than solid state reaction method, with he grain size of samples is around 150–250 nm. The results of vibrating sample magnetometer (VSM) showed the paramagnetic properties for all samples.« less

Improved accuracy for finite element structural analysis via a new integrated force method

NASA Technical Reports Server (NTRS)

Patnaik, Surya N.; Hopkins, Dale A.; Aiello, Robert A.; Berke, Laszlo

1992-01-01

A comparative study was carried out to determine the accuracy of finite element analyses based on the stiffness method, a mixed method, and the new integrated force and dual integrated force methods. The numerical results were obtained with the following software: MSC/NASTRAN and ASKA for the stiffness method; an MHOST implementation method for the mixed method; and GIFT for the integrated force methods. The results indicate that on an overall basis, the stiffness and mixed methods present some limitations. The stiffness method generally requires a large number of elements in the model to achieve acceptable accuracy. The MHOST method tends to achieve a higher degree of accuracy for course models than does the stiffness method implemented by MSC/NASTRAN and ASKA. The two integrated force methods, which bestow simultaneous emphasis on stress equilibrium and strain compatibility, yield accurate solutions with fewer elements in a model. The full potential of these new integrated force methods remains largely unexploited, and they hold the promise of spawning new finite element structural analysis tools.

Analysis of Flexible Bars and Frames with Large Displacements of Nodes By Finite Element Method in the Form of Classical Mixed Method

NASA Astrophysics Data System (ADS)

Ignatyev, A. V.; Ignatyev, V. A.; Onischenko, E. V.

2017-11-01

This article is the continuation of the work made bt the authors on the development of the algorithms that implement the finite element method in the form of a classical mixed method for the analysis of geometrically nonlinear bar systems [1-3]. The paper describes an improved algorithm of the formation of the nonlinear governing equations system for flexible plane frames and bars with large displacements of nodes based on the finite element method in a mixed classical form and the use of the procedure of step-by-step loading. An example of the analysis is given.

A New Linearized Crank-Nicolson Mixed Element Scheme for the Extended Fisher-Kolmogorov Equation

PubMed Central

Wang, Jinfeng; Li, Hong; He, Siriguleng; Gao, Wei

2013-01-01

We present a new mixed finite element method for solving the extended Fisher-Kolmogorov (EFK) equation. We first decompose the EFK equation as the two second-order equations, then deal with a second-order equation employing finite element method, and handle the other second-order equation using a new mixed finite element method. In the new mixed finite element method, the gradient ∇u belongs to the weaker (L 2(Ω))2 space taking the place of the classical H(div; Ω) space. We prove some a priori bounds for the solution for semidiscrete scheme and derive a fully discrete mixed scheme based on a linearized Crank-Nicolson method. At the same time, we get the optimal a priori error estimates in L 2 and H 1-norm for both the scalar unknown u and the diffusion term w = −Δu and a priori error estimates in (L 2)2-norm for its gradient χ = ∇u for both semi-discrete and fully discrete schemes. PMID:23864831

A new linearized Crank-Nicolson mixed element scheme for the extended Fisher-Kolmogorov equation.

PubMed

Wang, Jinfeng; Li, Hong; He, Siriguleng; Gao, Wei; Liu, Yang

2013-01-01

We present a new mixed finite element method for solving the extended Fisher-Kolmogorov (EFK) equation. We first decompose the EFK equation as the two second-order equations, then deal with a second-order equation employing finite element method, and handle the other second-order equation using a new mixed finite element method. In the new mixed finite element method, the gradient ∇u belongs to the weaker (L²(Ω))² space taking the place of the classical H(div; Ω) space. We prove some a priori bounds for the solution for semidiscrete scheme and derive a fully discrete mixed scheme based on a linearized Crank-Nicolson method. At the same time, we get the optimal a priori error estimates in L² and H¹-norm for both the scalar unknown u and the diffusion term w = -Δu and a priori error estimates in (L²)²-norm for its gradient χ = ∇u for both semi-discrete and fully discrete schemes.

Mixed-Methods Design in Biology Education Research: Approach and Uses.

PubMed

Warfa, Abdi-Rizak M

Educational research often requires mixing different research methodologies to strengthen findings, better contextualize or explain results, or minimize the weaknesses of a single method. This article provides practical guidelines on how to conduct such research in biology education, with a focus on mixed-methods research (MMR) that uses both quantitative and qualitative inquiries. Specifically, the paper provides an overview of mixed-methods design typologies most relevant in biology education research. It also discusses common methodological issues that may arise in mixed-methods studies and ways to address them. The paper concludes with recommendations on how to report and write about MMR. © 2016 L. A.-R. M. Warfa. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

A systematic review of mixed methods research on human factors and ergonomics in health care.

PubMed

Carayon, Pascale; Kianfar, Sarah; Li, Yaqiong; Xie, Anping; Alyousef, Bashar; Wooldridge, Abigail

2015-11-01

This systematic literature review provides information on the use of mixed methods research in human factors and ergonomics (HFE) research in health care. Using the PRISMA methodology, we searched four databases (PubMed, PsycInfo, Web of Science, and Engineering Village) for studies that met the following inclusion criteria: (1) field study in health care, (2) mixing of qualitative and quantitative data, (3) HFE issues, and (4) empirical evidence. Using an iterative and collaborative process supported by a structured data collection form, the six authors identified a total of 58 studies that primarily address HFE issues in health information technology (e.g., usability) and in the work of healthcare workers. About two-thirds of the mixed methods studies used the convergent parallel study design where quantitative and qualitative data were collected simultaneously. A variety of methods were used for collecting data, including interview, survey and observation. The most frequent combination involved interview for qualitative data and survey for quantitative data. The use of mixed methods in healthcare HFE research has increased over time. However, increasing attention should be paid to the formal literature on mixed methods research to enhance the depth and breadth of this research. Copyright © 2015. Published by Elsevier Ltd.

Reflections on the added value of using mixed methods in the SCAPE study.

PubMed

Murphy, Kathy; Casey, Dympna; Devane, Declan; Meskell, Pauline; Higgins, Agnes; Elliot, Naomi; Lalor, Joan; Begley, Cecily

2014-03-01

To reflect on the added value that a mixed method design gave in a large national evaluation study of specialist and advanced practice (SCAPE), and to propose a reporting guide that could help make explicit the added value of mixed methods in other studies. Recently, researchers have focused on how to carry out mixed methods research (MMR) rigorously. The value-added claims for MMR include the capacity to exploit the strengths and compensate for weakness inherent in single designs, generate comprehensive description of phenomena, produce more convincing results for funders or policy-makers and build methodological expertise. Data illustrating value added claims were drawn from the SCAPE study. Studies about the purpose of mixed methods were identified from a search of literature. The authors explain why and how they undertook components of the study, and propose a guideline to facilitate such studies. If MMR is to become the third methodological paradigm, then articulation of what extra benefit MMR adds to a study is essential. The authors conclude that MMR has added value and found the guideline useful as a way of making value claims explicit. The clear articulation of the procedural aspects of mixed-methods research, and identification of a guideline to facilitate such research, will enable researchers to learn more effectively from each other.

Designing A Mixed Methods Study In Primary Care

PubMed Central

Creswell, John W.; Fetters, Michael D.; Ivankova, Nataliya V.

2004-01-01

BACKGROUND Mixed methods or multimethod research holds potential for rigorous, methodologically sound investigations in primary care. The objective of this study was to use criteria from the literature to evaluate 5 mixed methods studies in primary care and to advance 3 models useful for designing such investigations. METHODS We first identified criteria from the social and behavioral sciences to analyze mixed methods studies in primary care research. We then used the criteria to evaluate 5 mixed methods investigations published in primary care research journals. RESULTS Of the 5 studies analyzed, 3 included a rationale for mixing based on the need to develop a quantitative instrument from qualitative data or to converge information to best understand the research topic. Quantitative data collection involved structured interviews, observational checklists, and chart audits that were analyzed using descriptive and inferential statistical procedures. Qualitative data consisted of semistructured interviews and field observations that were analyzed using coding to develop themes and categories. The studies showed diverse forms of priority: equal priority, qualitative priority, and quantitative priority. Data collection involved quantitative and qualitative data gathered both concurrently and sequentially. The integration of the quantitative and qualitative data in these studies occurred between data analysis from one phase and data collection from a subsequent phase, while analyzing the data, and when reporting the results. DISCUSSION We recommend instrument-building, triangulation, and data transformation models for mixed methods designs as useful frameworks to add rigor to investigations in primary care. We also discuss the limitations of our study and the need for future research. PMID:15053277

Combining qualitative and quantitative research within mixed method research designs: a methodological review.

PubMed

Östlund, Ulrika; Kidd, Lisa; Wengström, Yvonne; Rowa-Dewar, Neneh

2011-03-01

It has been argued that mixed methods research can be useful in nursing and health science because of the complexity of the phenomena studied. However, the integration of qualitative and quantitative approaches continues to be one of much debate and there is a need for a rigorous framework for designing and interpreting mixed methods research. This paper explores the analytical approaches (i.e. parallel, concurrent or sequential) used in mixed methods studies within healthcare and exemplifies the use of triangulation as a methodological metaphor for drawing inferences from qualitative and quantitative findings originating from such analyses. This review of the literature used systematic principles in searching CINAHL, Medline and PsycINFO for healthcare research studies which employed a mixed methods approach and were published in the English language between January 1999 and September 2009. In total, 168 studies were included in the results. Most studies originated in the United States of America (USA), the United Kingdom (UK) and Canada. The analytic approach most widely used was parallel data analysis. A number of studies used sequential data analysis; far fewer studies employed concurrent data analysis. Very few of these studies clearly articulated the purpose for using a mixed methods design. The use of the methodological metaphor of triangulation on convergent, complementary, and divergent results from mixed methods studies is exemplified and an example of developing theory from such data is provided. A trend for conducting parallel data analysis on quantitative and qualitative data in mixed methods healthcare research has been identified in the studies included in this review. Using triangulation as a methodological metaphor can facilitate the integration of qualitative and quantitative findings, help researchers to clarify their theoretical propositions and the basis of their results. This can offer a better understanding of the links between theory and empirical findings, challenge theoretical assumptions and develop new theory. Copyright © 2010 Elsevier Ltd. All rights reserved.

Development and application of a statistical quality assessment method for dense-graded mixes.

DOT National Transportation Integrated Search

2004-08-01

This report describes the development of the statistical quality assessment method and the procedure for mapping the measures obtained from the quality assessment method to a composite pay factor. The application to dense-graded mixes is demonstrated...

Effect of mixing method on the mixing degree during the preparation of triturations.

PubMed

Nakamura, Hitoshi; Yanagihara, Yoshitsugu; Sekiguchi, Hiroko; Komada, Fusao; Kawabata, Haruno; Ohtani, Michiteru; Saitoh, Yukiya; Kariya, Satoru; Suzuki, Hiroshi; Uchino, Katsuyoshi; Iga, Tatsuji

2004-03-01

By using lactose colored with erythrocin, we investigated the effects of mixing methods on mixing degree during the preparation of trituration with a mortar and pestle. The extent of powder dilution was set to 4 to 64 fold in the experiments. We compared the results obtained by using two methods: (1) one-step mixing of powders after addition of diluents and (2) gradual mixing of powders after addition of diluents. As diluents, we used crystallized lactose and powdered lactose for the preparation of trituration. In the preparation of 64-fold trituration, an excellent degree of mixing was obtained, with CV values of less than 6.08%, for both preparation methods and for the two kinds of diluents. The mixing of two kinds of powders whose distributions of particle sizes were similar resulted in much better degree of mixing, with CV values of less than 3.0%. However, the concentration of principal agents in 64-fold trituration was reduced by 20% due to the adsorption of dye to the apparatus. Under conditions in which a much higher dilution rate and/or much better degree of dilution was required, it must be necessary to dilute powders with considering their physicality and to determine the concentrations of principal agents after the mixing.

A demonstration of mixed-methods research in the health sciences.

PubMed

Katz, Janet; Vandermause, Roxanne; McPherson, Sterling; Barbosa-Leiker, Celestina

2016-11-18

Background The growth of patient, community and population-centred nursing research is a rationale for the use of research methods that can examine complex healthcare issues, not only from a biophysical perspective, but also from cultural, psychosocial and political viewpoints. This need for multiple perspectives requires mixed-methods research. Philosophy and practicality are needed to plan, conduct, and make mixed-methods research more broadly accessible to the health sciences research community. The traditions and dichotomy between qualitative and quantitative research makes the application of mixed methods a challenge. Aim To propose an integrated model for a research project containing steps from start to finish, and to use the unique strengths brought by each approach to meet the health needs of patients and communities. Discussion Mixed-methods research is a practical approach to inquiry, that focuses on asking questions and how best to answer them to improve the health of individuals, communities and populations. An integrated model of research begins with the research question(s) and moves in a continuum. The lines dividing methods do not dissolve, but become permeable boundaries where two or more methods can be used to answer research questions more completely. Rigorous and expert methodologists work together to solve common problems. Conclusion Mixed-methods research enables discussion among researchers from varied traditions. There is a plethora of methodological approaches available. Combining expertise by communicating across disciplines and professions is one way to tackle large and complex healthcare issues. Implications for practice The model presented in this paper exemplifies the integration of multiple approaches in a unified focus on identified phenomena. The dynamic nature of the model signals a need to be open to the data generated and the methodological directions implied by findings.

Mixed Methods Research in the Development and Evaluation of Complex Interventions in Palliative and End-of-Life Care: Report on the MORECare Consensus Exercise

PubMed Central

Preston, Nancy; Evans, Catherine J.; Grande, Gunn; Short, Vicky; Benalia, Hamid; Higginson, Irene J.; Todd, on behalf of MORECare, Chris

2013-01-01

Abstract Background: Complex interventions are common in palliative and end-of-life care. Mixed methods approaches sit well within the multiphase model of complex intervention development and evaluation. Generic mixed methods guidance is useful but additional challenges in the research design and operationalization within palliative and end-of-life care may have an impact on the use of mixed methods. Objective: The objective of the study was to develop guidance on the best methods for combining quantitative and qualitative methods for health and social care intervention development and evaluation in palliative and end-of-life care. Methods: A one-day workshop was held where experts participated in facilitated groups using Transparent Expert Consultation to generate items for potential recommendations. Agreement and consensus were then sought on nine draft recommendations (DRs) in a follow-up exercise. Results: There was at least moderate agreement with most of the DRs, although consensus was low. Strongest agreement was with DR1 (usefulness of mixed methods to palliative and end-of-life care) and DR5 (importance of attention to respondent burden), and least agreement was with DR2 (use of theoretical perspectives) and DR6 (therapeutic effects of research interviews). Narrative comments enabled recommendation refinement. Two fully endorsed, five partially endorsed, and two refined DRs emerged. The relationship of these nine to six key challenges of palliative and end-of-life care research was analyzed. Conclusions: There is a need for further discussion of these recommendations and their contribution to methodology. The recommendations should be considered when designing and operationalizing mixed methods studies of complex interventions in palliative care, and because they may have wider relevance, should be considered for other applications. PMID:24195755

Mixing in microfluidic devices and enhancement methods

PubMed Central

Ward, Kevin; Fan, Z Hugh

2015-01-01

Mixing in microfluidic devices presents a challenge due to laminar flows in microchannels, which result from low Reynolds numbers determined by the channel’s hydraulic diameter, flow velocity, and solution’s kinetic viscosity. To address this challenge, novel methods of mixing enhancement within microfluidic devices have been explored for a variety of applications. Passive mixing methods have been created, including those using ridges or slanted wells within the microchannels, as well as their variations with improved performance by varying geometry and patterns, by changing the properties of channel surfaces, and by optimization via simulations. In addition, active mixing methods including microstirrers, acoustic mixers, and flow pulsation have been investigated and integrated into microfluidic devices to enhance mixing in a more controllable manner. In general, passive mixers are easy to integrate, but difficult to control externally by users after fabrication. Active mixers usually take efforts to integrate within a device and they require external components (e.g. power sources) to operate. However, they can be controlled by users to a certain degree for tuned mixing. In this article, we provide a general overview of a number of passive and active mixers, discuss their advantages and disadvantages, and make suggestions on choosing a mixing method for a specific need as well as advocate possible integration of key elements of passive and active mixers to harness the advantages of both types. PMID:26549938

Mixing in microfluidic devices and enhancement methods.

PubMed

Ward, Kevin; Fan, Z Hugh

2015-09-01

Mixing in microfluidic devices presents a challenge due to laminar flows in microchannels, which result from low Reynolds numbers determined by the channel's hydraulic diameter, flow velocity, and solution's kinetic viscosity. To address this challenge, novel methods of mixing enhancement within microfluidic devices have been explored for a variety of applications. Passive mixing methods have been created, including those using ridges or slanted wells within the microchannels, as well as their variations with improved performance by varying geometry and patterns, by changing the properties of channel surfaces, and by optimization via simulations. In addition, active mixing methods including microstirrers, acoustic mixers, and flow pulsation have been investigated and integrated into microfluidic devices to enhance mixing in a more controllable manner. In general, passive mixers are easy to integrate, but difficult to control externally by users after fabrication. Active mixers usually take efforts to integrate within a device and they require external components (e.g. power sources) to operate. However, they can be controlled by users to a certain degree for tuned mixing. In this article, we provide a general overview of a number of passive and active mixers, discuss their advantages and disadvantages, and make suggestions on choosing a mixing method for a specific need as well as advocate possible integration of key elements of passive and active mixers to harness the advantages of both types.

Mixing a Grounded Theory Approach with a Randomized Controlled Trial Related to Intimate Partner Violence: What Challenges Arise for Mixed Methods Research?

PubMed Central

Catallo, Cristina; Jack, Susan M.; Ciliska, Donna; MacMillan, Harriet L.

2013-01-01

Little is known about how to systematically integrate complex qualitative studies within the context of randomized controlled trials. A two-phase sequential explanatory mixed methods study was conducted in Canada to understand how women decide to disclose intimate partner violence in emergency department settings. Mixing a RCT (with a subanalysis of data) with a grounded theory approach required methodological modifications to maintain the overall rigour of this mixed methods study. Modifications were made to the following areas of the grounded theory approach to support the overall integrity of the mixed methods study design: recruitment of participants, maximum variation and negative case sampling, data collection, and analysis methods. Recommendations for future studies include: (1) planning at the outset to incorporate a qualitative approach with a RCT and to determine logical points during the RCT to integrate the qualitative component and (2) consideration for the time needed to carry out a RCT and a grounded theory approach, especially to support recruitment, data collection, and analysis. Data mixing strategies should be considered during early stages of the study, so that appropriate measures can be developed and used in the RCT to support initial coding structures and data analysis needs of the grounded theory phase. PMID:23577245

An equivalent domain integral method for three-dimensional mixed-mode fracture problems

NASA Technical Reports Server (NTRS)

Shivakumar, K. N.; Raju, I. S.

1991-01-01

A general formulation of the equivalent domain integral (EDI) method for mixed mode fracture problems in cracked solids is presented. The method is discussed in the context of a 3-D finite element analysis. The J integral consists of two parts: the volume integral of the crack front potential over a torus enclosing the crack front and the crack surface integral due to the crack front potential plus the crack face loading. In mixed mode crack problems the total J integral is split into J sub I, J sub II, and J sub III representing the severity of the crack front in three modes of deformations. The direct and decomposition methods are used to separate the modes. These two methods were applied to several mixed mode fracture problems, were analyzed, and results were found to agree well with those available in the literature. The method lends itself to be used as a post-processing subroutine in a general purpose finite element program.

An equivalent domain integral method for three-dimensional mixed-mode fracture problems

NASA Technical Reports Server (NTRS)

Shivakumar, K. N.; Raju, I. S.

1992-01-01

A general formulation of the equivalent domain integral (EDI) method for mixed mode fracture problems in cracked solids is presented. The method is discussed in the context of a 3-D finite element analysis. The J integral consists of two parts: the volume integral of the crack front potential over a torus enclosing the crack front and the crack surface integral due to the crack front potential plus the crack face loading. In mixed mode crack problems the total J integral is split into J sub I, J sub II, and J sub III representing the severity of the crack front in three modes of deformations. The direct and decomposition methods are used to separate the modes. These two methods were applied to several mixed mode fracture problems, were analyzed, and results were found to agree well with those available in the literature. The method lends itself to be used as a post-processing subroutine in a general purpose finite element program.

Recent Development of Multigrid Algorithms for Mixed and Noncomforming Methods for Second Order Elliptical Problems

NASA Technical Reports Server (NTRS)

Chen, Zhangxin; Ewing, Richard E.

1996-01-01

Multigrid algorithms for nonconforming and mixed finite element methods for second order elliptic problems on triangular and rectangular finite elements are considered. The construction of several coarse-to-fine intergrid transfer operators for nonconforming multigrid algorithms is discussed. The equivalence between the nonconforming and mixed finite element methods with and without projection of the coefficient of the differential problems into finite element spaces is described.

Existence and stability, and discrete BB and rank conditions, for general mixed-hybrid finite elements in elasticity

NASA Technical Reports Server (NTRS)

Xue, W.-M.; Atluri, S. N.

1985-01-01

In this paper, all possible forms of mixed-hybrid finite element methods that are based on multi-field variational principles are examined as to the conditions for existence, stability, and uniqueness of their solutions. The reasons as to why certain 'simplified hybrid-mixed methods' in general, and the so-called 'simplified hybrid-displacement method' in particular (based on the so-called simplified variational principles), become unstable, are discussed. A comprehensive discussion of the 'discrete' BB-conditions, and the rank conditions, of the matrices arising in mixed-hybrid methods, is given. Some recent studies aimed at the assurance of such rank conditions, and the related problem of the avoidance of spurious kinematic modes, are presented.

Application of the control volume mixed finite element method to a triangular discretization

USGS Publications Warehouse

Naff, R.L.

2012-01-01

A two-dimensional control volume mixed finite element method is applied to the elliptic equation. Discretization of the computational domain is based in triangular elements. Shape functions and test functions are formulated on the basis of an equilateral reference triangle with unit edges. A pressure support based on the linear interpolation of elemental edge pressures is used in this formulation. Comparisons are made between results from the standard mixed finite element method and this control volume mixed finite element method. Published 2011. This article is a US Government work and is in the public domain in the USA. ?? 2012 John Wiley & Sons, Ltd. This article is a US Government work and is in the public domain in the USA.

Designing a mixed methods study in primary care.

PubMed

Creswell, John W; Fetters, Michael D; Ivankova, Nataliya V

2004-01-01

Mixed methods or multimethod research holds potential for rigorous, methodologically sound investigations in primary care. The objective of this study was to use criteria from the literature to evaluate 5 mixed methods studies in primary care and to advance 3 models useful for designing such investigations. We first identified criteria from the social and behavioral sciences to analyze mixed methods studies in primary care research. We then used the criteria to evaluate 5 mixed methods investigations published in primary care research journals. Of the 5 studies analyzed, 3 included a rationale for mixing based on the need to develop a quantitative instrument from qualitative data or to converge information to best understand the research topic. Quantitative data collection involved structured interviews, observational checklists, and chart audits that were analyzed using descriptive and inferential statistical procedures. Qualitative data consisted of semistructured interviews and field observations that were analyzed using coding to develop themes and categories. The studies showed diverse forms of priority: equal priority, qualitative priority, and quantitative priority. Data collection involved quantitative and qualitative data gathered both concurrently and sequentially. The integration of the quantitative and qualitative data in these studies occurred between data analysis from one phase and data collection from a subsequent phase, while analyzing the data, and when reporting the results. We recommend instrument-building, triangulation, and data transformation models for mixed methods designs as useful frameworks to add rigor to investigations in primary care. We also discuss the limitations of our study and the need for future research.

Examining mixing methods in an evaluation of a smoking cessation program.

PubMed

Betzner, Anne; Lawrenz, Frances P; Thao, Mao

2016-02-01

Three different methods were used in an evaluation of a smoking cessation study: surveys, focus groups, and phenomenological interviews. The results of each method were analyzed separately and then combined using both a pragmatic and dialectic stance to examine the effects of different approaches to mixing methods. Results show that the further apart the methods are philosophically, the more diverse the findings. Comparisons of decision maker opinions and costs of the different methods are provided along with recommendations for evaluators' uses of different methods. Copyright © 2015. Published by Elsevier Ltd.

Reconciling Data from Different Sources: Practical Realities of Using Mixed Methods to Identify Effective High School Practices

ERIC Educational Resources Information Center

Smith, Thomas M.; Cannata, Marisa; Haynes, Katherine Taylor

2016-01-01

Background/Context: Mixed methods research conveys multiple advantages to the study of complex phenomena and large organizations or systems. The benefits are derived from drawing on the strengths of qualitative methods to answer questions about how and why a phenomenon occurs and those of quantitative methods to examine how often a phenomenon…

Mixed Method Research in Special Education.

ERIC Educational Resources Information Center

McWilliam, R. A.

This paper addresses the conditions under which quantitative and qualitative research methods could be combined in special education. The paper asserts that qualitative designs have not had a significant effect on special education research and speculates that mixed-method research might be more acceptable to special education researchers or…

Mixed Methods Research Designs in Counseling Psychology

ERIC Educational Resources Information Center

Hanson, William E.; Creswell, John W.; Clark, Vicki L. Plano; Petska, Kelly S.; Creswell, David J.

2005-01-01

With the increased popularity of qualitative research, researchers in counseling psychology are expanding their methodologies to include mixed methods designs. These designs involve the collection, analysis, and integration of quantitative and qualitative data in a single or multiphase study. This article presents an overview of mixed methods…

Use of NDT equipment for construction quality control of hot mix asphalt pavements

DOT National Transportation Integrated Search

2006-08-01

The focus of the study has been to evaluate the utility of seismic methods in the quality management of the hot mix asphalt layers. Procedures are presented to measure the target field moduli of hot mix asphalt (HMA) with laboratory seismic methods, ...

A mixed methods contribution to the study of health public policies: complementarities and difficulties

PubMed Central

2015-01-01

The use of mixed methods (combining quantitative and qualitative data) is developing in a variety of forms, especially in the health field. Our own research has adopted this perspective from the outset. We have sought all along to innovate in various ways and especially to develop an equal partnership, in the sense of not allowing any single approach to dominate. After briefly describing mixed methods, in this article we explain and illustrate how we have exploited both qualitative and quantitative methods to answer our research questions, ending with a reflective analysis of our experiment. PMID:26559730

Synthesis of soluble conducting polymers by acoustic mixing

DOEpatents

Kane, Marie C.

2016-09-13

A method including combining an aniline monomer, an oxidant, water and an organic solvent; subjecting the combination to acoustic mixing to form an emulsion; and recovering a polyaniliine from the combination. A method including combining a aniline monomer, an oxidant, water and an organic solvent; forming a polyaniline by acoustic mixing the combination; and recovering the polyaniliine from the combination. A method including forming a combination of an aniline monomer, an oxidant, water and an organic solvent in the absence of an emulsifier; acoustic mixing the combination for a time period to form a polyaniline; and recovering a polyaniliine from the combination.

Analytical and quasi-Bayesian methods as development of the iterative approach for mixed radiation biodosimetry.

PubMed

Słonecka, Iwona; Łukasik, Krzysztof; Fornalski, Krzysztof W

2018-06-04

The present paper proposes two methods of calculating components of the dose absorbed by the human body after exposure to a mixed neutron and gamma radiation field. The article presents a novel approach to replace the common iterative method in its analytical form, thus reducing the calculation time. It also shows a possibility of estimating the neutron and gamma doses when their ratio in a mixed beam is not precisely known.

Retrieval of constituent mixing ratios from limb thermal emission spectra

NASA Technical Reports Server (NTRS)

Shaffer, William A.; Kunde, Virgil G.; Conrath, Barney J.

1988-01-01

An onion-peeling iterative, least-squares relaxation method to retrieve mixing ratio profiles from limb thermal emission spectra is presented. The method has been tested on synthetic data, containing various amounts of added random noise for O3, HNO3, and N2O. The retrieval method is used to obtain O3 and HNO3 mixing ratio profiles from high-resolution thermal emission spectra. Results of the retrievals compare favorably with those obtained previously.

Qualitative and mixed methods in mental health services and implementation research.

PubMed

Palinkas, Lawrence A

2014-01-01

Qualitative and mixed methods play a prominent role in mental health services research. However, the standards for their use are not always evident, especially for those not trained in such methods. This article reviews the rationale and common approaches to using qualitative and mixed methods in mental health services and implementation research based on a review of the articles included in this special series along with representative examples from the literature. Qualitative methods are used to provide a "thick description" or depth of understanding to complement breadth of understanding afforded by quantitative methods, elicit the perspective of those being studied, explore issues that have not been well studied, develop conceptual theories or test hypotheses, or evaluate the process of a phenomenon or intervention. Qualitative methods adhere to many of the same principles of scientific rigor as quantitative methods but often differ with respect to study design, data collection, and data analysis strategies. For instance, participants for qualitative studies are usually sampled purposefully rather than at random and the design usually reflects an iterative process alternating between data collection and analysis. The most common techniques for data collection are individual semistructured interviews, focus groups, document reviews, and participant observation. Strategies for analysis are usually inductive, based on principles of grounded theory or phenomenology. Qualitative methods are also used in combination with quantitative methods in mixed-method designs for convergence, complementarity, expansion, development, and sampling. Rigorously applied qualitative methods offer great potential in contributing to the scientific foundation of mental health services research.

Searching for Rigour in the Reporting of Mixed Methods Population Health Research: A Methodological Review

ERIC Educational Resources Information Center

Brown, K. M.; Elliott, S. J.; Leatherdale, S. T.; Robertson-Wilson, J.

2015-01-01

The environments in which population health interventions occur shape both their implementation and outcomes. Hence, when evaluating these interventions, we must explore both intervention content and context. Mixed methods (integrating quantitative and qualitative methods) provide this opportunity. However, although criteria exist for establishing…

Enhancing Learning Outcomes through Evaluation of Serious Gaming: A Mixed Methods Study

ERIC Educational Resources Information Center

Douglas, Kerrie Anna

2012-01-01

This study compared the change in counseling student's self-efficacy and skill related to suicide assessment and intervention through the use of a novel intervention-oriented evaluation method, evaluation focused discussion groups, in an experimental embedded mixed methods design. An innovation counselor pedagogical tool, Suicide Risk Assessment…

A Mixed-Methods Longitudinal Evaluation of a One-Day Mental Health Wellness Intervention

ERIC Educational Resources Information Center

Doyle, Louise; de Vries, Jan; Higgins, Agnes; Keogh, Brian; McBennett, Padraig; O'Shea, Marié T.

2017-01-01

Objectives: This study evaluated the impact of a one-day mental health Wellness Workshop on participants' mental health and attitudes towards mental health. Design: Convergent, longitudinal mixed-methods approach. Setting: The study evaluated Wellness Workshops which took place throughout the Republic of Ireland. Method: Questionnaires measuring…

Creating and supporting a mixed methods health services research team.

PubMed

Bowers, Barbara; Cohen, Lauren W; Elliot, Amy E; Grabowski, David C; Fishman, Nancy W; Sharkey, Siobhan S; Zimmerman, Sheryl; Horn, Susan D; Kemper, Peter

2013-12-01

To use the experience from a health services research evaluation to provide guidance in team development for mixed methods research. The Research Initiative Valuing Eldercare (THRIVE) team was organized by the Robert Wood Johnson Foundation to evaluate The Green House nursing home culture change program. This article describes the development of the research team and provides insights into how funders might engage with mixed methods research teams to maximize the value of the team. Like many mixed methods collaborations, the THRIVE team consisted of researchers from diverse disciplines, embracing diverse methodologies, and operating under a framework of nonhierarchical, shared leadership that required new collaborations, engagement, and commitment in the context of finite resources. Strategies to overcome these potential obstacles and achieve success included implementation of a Coordinating Center, dedicated time for planning and collaborating across researchers and methodologies, funded support for in-person meetings, and creative optimization of resources. Challenges are inevitably present in the formation and operation of effective mixed methods research teams. However, funders and research teams can implement strategies to promote success. © Health Research and Educational Trust.

Para-Quantitative Methodology: Reclaiming Experimentalism in Educational Research

ERIC Educational Resources Information Center

Shabani Varaki, Bakhtiar; Floden, Robert E.; Javidi Kalatehjafarabadi, Tahereh

2015-01-01

This article focuses on the criticisms of current approaches in educational research methodology. It summarizes rationales for mixed methods and argues that the mixing quantitative paradigm and qualitative paradigm is problematic due to practical and philosophical arguments. It is also indicated that the current rise of mixed methods work has…

The existence results and Tikhonov regularization method for generalized mixed variational inequalities in Banach spaces

NASA Astrophysics Data System (ADS)

Wang, Min

2017-06-01

This paper aims to establish the Tikhonov regularization method for generalized mixed variational inequalities in Banach spaces. For this purpose, we firstly prove a very general existence result for generalized mixed variational inequalities, provided that the mapping involved has the so-called mixed variational inequality property and satisfies a rather weak coercivity condition. Finally, we establish the Tikhonov regularization method for generalized mixed variational inequalities. Our findings extended the results for the generalized variational inequality problem (for short, GVIP( F, K)) in R^n spaces (He in Abstr Appl Anal, 2012) to the generalized mixed variational inequality problem (for short, GMVIP(F,φ , K)) in reflexive Banach spaces. On the other hand, we generalized the corresponding results for the generalized mixed variational inequality problem (for short, GMVIP(F,φ ,K)) in R^n spaces (Fu and He in J Sichuan Norm Univ (Nat Sci) 37:12-17, 2014) to reflexive Banach spaces.

A Mixed Methods Study of Teach for America Teachers' Mathematical Beliefs, Knowledge, and Classroom Teaching Practices during a Reform-Based University Mathematics Methods Course

ERIC Educational Resources Information Center

Swars, Susan Lee

2015-01-01

This mixed methods study examined the mathematical preparation of elementary teachers in a Teach for America (TFA) program, focal participants for whom there is scant extant research. Data collection occurred before and after a university mathematics methods course, with a particular focus on the participants' (n = 22) mathematical beliefs,…

Effect of Resin-modified Glass Ionomer Cement Dispensing/Mixing Methods on Mechanical Properties.

PubMed

Sulaiman, T A; Abdulmajeed, A A; Altitinchi, A; Ahmed, S N; Donovan, T E

2018-03-23

Resin-modified glass ionomer cements (RMGIs) are often used for luting indirect restorations. Hand-mixing traditional cements demands significant time and may be technique sensitive. Efforts have been made by manufacturers to introduce the same cement using different dispensing/mixing methods. It is not known what effects these changes may have on the mechanical properties of the dental cement. The purpose of this study was to evaluate the mechanical properties (diametral tensile strength [DTS], compressive strength [CS], and fracture toughness [FT]) of RMGIs with different dispensing/mixing systems. The RMGI specimens (n=14)-RelyX Luting (hand mix), RelyX Luting Plus (clicker-hand mix), RelyX Luting Plus (automix) (3M ESPE), GC Fuji PLUS (capsule-automix), and GC FujiCEM 2 (automix) (GC)-were prepared for each mechanical test and examined after thermocycling (n=7/subgroup) for 20,000 cycles to the following: DTS, CS (ISO 9917-1) and FT (ISO standard 6872; Single-edge V-notched beam method). Specimens were mounted and loaded with a universal testing machine until failure occurred. Two-/one-way analysis of variance followed by Tukey honestly significantly different post hoc test was used to analyze data for statistical significance ( p<0.05). The interaction effect of both dispensing/mixing method and thermocycling was significant only for the CS test of the GC group ( p<0.05). The different dispensing/mixing methods had no effect on the DTS of the tested cements. The CS of GC Fuji PLUS was significantly higher than that of the automix version ( p<0.05). The FT decreased significantly when switching from RelyX (hand mix) to RelyX Luting Plus (clicker-hand mix) and to RelyX Luting Plus (automix) ( p<0.05). Except in the case of the DTS of the GC group and the CS of GC Fuji PLUS, thermocycling had a significant effect reducing the mechanical properties of the RMGI cements ( p<0.05). Introducing alternative dispensing/mixing methods for mixing RMGIs to reduce time and technique sensitivity may affect mechanical properties and is brand dependent.

Results of Propellant Mixing Variable Study Using Precise Pressure-Based Burn Rate Calculations

NASA Technical Reports Server (NTRS)

Stefanski, Philip L.

2014-01-01

A designed experiment was conducted in which three mix processing variables (pre-curative addition mix temperature, pre-curative addition mixing time, and mixer speed) were varied to estimate their effects on within-mix propellant burn rate variability. The chosen discriminator for the experiment was the 2-inch diameter by 4-inch long (2x4) Center-Perforated (CP) ballistic evaluation motor. Motor nozzle throat diameters were sized to produce a common targeted chamber pressure. Initial data analysis did not show a statistically significant effect. Because propellant burn rate must be directly related to chamber pressure, a method was developed that showed statistically significant effects on chamber pressure (either maximum or average) by adjustments to the process settings. Burn rates were calculated from chamber pressures and these were then normalized to a common pressure for comparative purposes. The pressure-based method of burn rate determination showed significant reduction in error when compared to results obtained from the Brooks' modification of the propellant web-bisector burn rate determination method. Analysis of effects using burn rates calculated by the pressure-based method showed a significant correlation of within-mix burn rate dispersion to mixing duration and the quadratic of mixing duration. The findings were confirmed in a series of mixes that examined the effects of mixing time on burn rate variation, which yielded the same results.

Mixed methods research in the development and evaluation of complex interventions in palliative and end-of-life care: report on the MORECare consensus exercise.

PubMed

Farquhar, Morag; Preston, Nancy; Evans, Catherine J; Grande, Gunn; Short, Vicky; Benalia, Hamid; Higginson, Irene J; Todd, Chris

2013-12-01

Complex interventions are common in palliative and end-of-life care. Mixed methods approaches sit well within the multiphase model of complex intervention development and evaluation. Generic mixed methods guidance is useful but additional challenges in the research design and operationalization within palliative and end-of-life care may have an impact on the use of mixed methods. The objective of the study was to develop guidance on the best methods for combining quantitative and qualitative methods for health and social care intervention development and evaluation in palliative and end-of-life care. A one-day workshop was held where experts participated in facilitated groups using Transparent Expert Consultation to generate items for potential recommendations. Agreement and consensus were then sought on nine draft recommendations (DRs) in a follow-up exercise. There was at least moderate agreement with most of the DRs, although consensus was low. Strongest agreement was with DR1 (usefulness of mixed methods to palliative and end-of-life care) and DR5 (importance of attention to respondent burden), and least agreement was with DR2 (use of theoretical perspectives) and DR6 (therapeutic effects of research interviews). Narrative comments enabled recommendation refinement. Two fully endorsed, five partially endorsed, and two refined DRs emerged. The relationship of these nine to six key challenges of palliative and end-of-life care research was analyzed. There is a need for further discussion of these recommendations and their contribution to methodology. The recommendations should be considered when designing and operationalizing mixed methods studies of complex interventions in palliative care, and because they may have wider relevance, should be considered for other applications.

Design and optimization of mixed flow pump impeller blades by varying semi-cone angle

NASA Astrophysics Data System (ADS)

Dash, Nehal; Roy, Apurba Kumar; Kumar, Kaushik

2018-03-01

The mixed flow pump is a cross between the axial and radial flow pump. These pumps are used in a large number of applications in modern fields. For the designing of these mixed flow pump impeller blades, a lot number of design parameters are needed to be considered which makes this a tedious task for which fundamentals of turbo-machinery and fluid mechanics are always prerequisites. The semi-cone angle of mixed flow pump impeller blade has a specified range of variations generally between 45o to 60o. From the literature review done related to this topic researchers have considered only a particular semi-cone angle and all the calculations are based on this very same semi-cone angle. By varying this semi-cone angle in the specified range, it can be verified if that affects the designing of the impeller blades for a mixed flow pump. Although a lot of methods are available for designing of mixed flow pump impeller blades like inverse time marching method, the pseudo-stream function method, Fourier expansion singularity method, free vortex method, mean stream line theory method etc. still the optimized design of the mixed flow pump impeller blade has been a cumbersome work. As stated above since all the available research works suggest or propose the blade designs with constant semi-cone angle, here the authors have designed the impeller blades by varying the semi-cone angle in a particular range with regular intervals for a Mixed-Flow pump. Henceforth several relevant impeller blade designs are obtained and optimization is carried out to obtain the optimized design (blade with optimal geometry) of impeller blade.

A Hybrid Numerical Method for Turbulent Mixing Layers. Degree awarded by Case Western Reserve Univ.

NASA Technical Reports Server (NTRS)

Georgiadis, Nicholas J.

2001-01-01

A hybrid method has been developed for simulations of compressible turbulent mixing layers. Such mixing layers dominate the flows in exhaust systems of modern day aircraft and also those of hypersonic vehicles currently under development. The method configurations in which a dominant structural feature provides an unsteady mechanism to drive the turbulent development in the mixing layer. The hybrid method uses a Reynolds-averaged Navier-Stokes (RANS) procedure to calculate wall bounded regions entering a mixing section, and a Large Eddy Simulation (LES) procedure to calculate the mixing dominated regions. A numerical technique was developed to enable the use of the hybrid RANS-LES method on stretched, non-Cartesian grids. Closure for the RANS equations was obtained using the Cebeci-Smith algebraic turbulence model in conjunction with the wall-function approach of Ota and Goldberg. The wall-function approach enabled a continuous computational grid from the RANS regions to the LES region. The LES equations were closed using the Smagorinsky subgrid scale model. The hybrid RANS-LES method is applied to a benchmark compressible mixing layer experiment. Preliminary two dimensional calculations are used to investigate the effects of axial grid density and boundary conditions. Vortex shedding from the base region of a splitter plate separating the upstream flows was observed to eventually transition to turbulence. The location of the transition, however, was much further downstream than indicated by experiments. Actual LES calculations, performed in three spatial directions, also indicated vortex shedding, but the transition to turbulence was found to occur much closer to the beginning of the mixing section. which is in agreement with experimental observations. These calculations demonstrated that LES simulations must be performed in three dimensions. Comparisons of time-averaged axial velocities and turbulence intensities indicated reasonable agreement with experimental data.

The role of mixed methods in improved cookstove research.

PubMed

Stanistreet, Debbi; Hyseni, Lirije; Bashin, Michelle; Sadumah, Ibrahim; Pope, Daniel; Sage, Michael; Bruce, Nigel

2015-01-01

The challenge of promoting access to clean and efficient household energy for cooking and heating is a critical issue facing low- and middle-income countries today. Along with clean fuels, improved cookstoves (ICSs) continue to play an important part in efforts to reduce the 4 million annual premature deaths attributed to household air pollution. Although a range of ICSs are available, there is little empirical evidence on appropriate behavior change approaches to inform adoption and sustained used at scale. Specifically, evaluations using either quantitative or qualitative methods provide an incomplete picture of the challenges in facilitating ICS adoption. This article examines how studies that use the strengths of both these approaches can offer important insights into behavior change in relation to ICS uptake and scale-up. Epistemological approaches, study design frameworks, methods of data collection, analytical approaches, and issues of validity and reliability in the context of mixed methods ICS research are examined, and the article presents an example study design from an evaluation study in Kenya incorporating a nested approach and a convergent case oriented design. The authors discuss the benefits and methodological challenges of mixed-methods approaches in the context of researching behavior change and ICS use recognizing that such methods represent relatively uncharted territory. The authors propose that more published examples are needed to provide frameworks for other researchers seeking to apply mixed methods in this context and suggest a comprehensive research agenda is required that incorporates integrated mixed-methods approaches, to provide best evidence for future scale-up.

Model's sparse representation based on reduced mixed GMsFE basis methods

NASA Astrophysics Data System (ADS)

Jiang, Lijian; Li, Qiuqi

2017-06-01

In this paper, we propose a model's sparse representation based on reduced mixed generalized multiscale finite element (GMsFE) basis methods for elliptic PDEs with random inputs. A typical application for the elliptic PDEs is the flow in heterogeneous random porous media. Mixed generalized multiscale finite element method (GMsFEM) is one of the accurate and efficient approaches to solve the flow problem in a coarse grid and obtain the velocity with local mass conservation. When the inputs of the PDEs are parameterized by the random variables, the GMsFE basis functions usually depend on the random parameters. This leads to a large number degree of freedoms for the mixed GMsFEM and substantially impacts on the computation efficiency. In order to overcome the difficulty, we develop reduced mixed GMsFE basis methods such that the multiscale basis functions are independent of the random parameters and span a low-dimensional space. To this end, a greedy algorithm is used to find a set of optimal samples from a training set scattered in the parameter space. Reduced mixed GMsFE basis functions are constructed based on the optimal samples using two optimal sampling strategies: basis-oriented cross-validation and proper orthogonal decomposition. Although the dimension of the space spanned by the reduced mixed GMsFE basis functions is much smaller than the dimension of the original full order model, the online computation still depends on the number of coarse degree of freedoms. To significantly improve the online computation, we integrate the reduced mixed GMsFE basis methods with sparse tensor approximation and obtain a sparse representation for the model's outputs. The sparse representation is very efficient for evaluating the model's outputs for many instances of parameters. To illustrate the efficacy of the proposed methods, we present a few numerical examples for elliptic PDEs with multiscale and random inputs. In particular, a two-phase flow model in random porous media is simulated by the proposed sparse representation method.

Model's sparse representation based on reduced mixed GMsFE basis methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Lijian, E-mail: ljjiang@hnu.edu.cn; Li, Qiuqi, E-mail: qiuqili@hnu.edu.cn

2017-06-01

In this paper, we propose a model's sparse representation based on reduced mixed generalized multiscale finite element (GMsFE) basis methods for elliptic PDEs with random inputs. A typical application for the elliptic PDEs is the flow in heterogeneous random porous media. Mixed generalized multiscale finite element method (GMsFEM) is one of the accurate and efficient approaches to solve the flow problem in a coarse grid and obtain the velocity with local mass conservation. When the inputs of the PDEs are parameterized by the random variables, the GMsFE basis functions usually depend on the random parameters. This leads to a largemore » number degree of freedoms for the mixed GMsFEM and substantially impacts on the computation efficiency. In order to overcome the difficulty, we develop reduced mixed GMsFE basis methods such that the multiscale basis functions are independent of the random parameters and span a low-dimensional space. To this end, a greedy algorithm is used to find a set of optimal samples from a training set scattered in the parameter space. Reduced mixed GMsFE basis functions are constructed based on the optimal samples using two optimal sampling strategies: basis-oriented cross-validation and proper orthogonal decomposition. Although the dimension of the space spanned by the reduced mixed GMsFE basis functions is much smaller than the dimension of the original full order model, the online computation still depends on the number of coarse degree of freedoms. To significantly improve the online computation, we integrate the reduced mixed GMsFE basis methods with sparse tensor approximation and obtain a sparse representation for the model's outputs. The sparse representation is very efficient for evaluating the model's outputs for many instances of parameters. To illustrate the efficacy of the proposed methods, we present a few numerical examples for elliptic PDEs with multiscale and random inputs. In particular, a two-phase flow model in random porous media is simulated by the proposed sparse representation method.« less

Students awareness of learning styles and their perceptions to a mixed method approach for learning

PubMed Central

Bhagat, Anumeha; Vyas, Rashmi; Singh, Tejinder

2015-01-01

Background: Individualization of instructional method does not contribute significantly to learning outcomes although it is known that students have differing learning styles (LSs). Hence, in order to maximally enhance learning, one must try to use a mixed method approach. Hypothesis: Our hypothesis was that awareness of preferred LS and motivation to incorporate multiple learning strategies might enhance learning outcomes. Aim: Our aim was to determine the impact of awareness of LS among medical undergraduates and motivating students to use mixed methods of learning. Materials and Methods: Before awareness lecture, LS preferences were determined using Visual, Aural, Read/Write, and Kinesthetic (VARK) questionnaire. Awareness of LS was assessed using a validated questionnaire. Through a lecture, students were oriented to various LSs, impact of LS on their performance, and benefit of using mixed method approach for learning. Subsequently, group discussions were organized. After 3 months, VARK preferences and awareness of LSs were reassessed. Student narratives were collected. Qualitative analysis of the data was done. Results: There was a significant increase in the number of students who were aware of LS. The number of participants showing a change in VARK scores for various modalities of learning was also significant (P < 0.001). Conclusion: Thus, awareness of LSs motivated students to adapt other learning strategies and use mixed methods for learning. PMID:26380214

Adapt-Mix: learning local genetic correlation structure improves summary statistics-based analyses

PubMed Central

Park, Danny S.; Brown, Brielin; Eng, Celeste; Huntsman, Scott; Hu, Donglei; Torgerson, Dara G.; Burchard, Esteban G.; Zaitlen, Noah

2015-01-01

Motivation: Approaches to identifying new risk loci, training risk prediction models, imputing untyped variants and fine-mapping causal variants from summary statistics of genome-wide association studies are playing an increasingly important role in the human genetics community. Current summary statistics-based methods rely on global ‘best guess’ reference panels to model the genetic correlation structure of the dataset being studied. This approach, especially in admixed populations, has the potential to produce misleading results, ignores variation in local structure and is not feasible when appropriate reference panels are missing or small. Here, we develop a method, Adapt-Mix, that combines information across all available reference panels to produce estimates of local genetic correlation structure for summary statistics-based methods in arbitrary populations. Results: We applied Adapt-Mix to estimate the genetic correlation structure of both admixed and non-admixed individuals using simulated and real data. We evaluated our method by measuring the performance of two summary statistics-based methods: imputation and joint-testing. When using our method as opposed to the current standard of ‘best guess’ reference panels, we observed a 28% decrease in mean-squared error for imputation and a 73.7% decrease in mean-squared error for joint-testing. Availability and implementation: Our method is publicly available in a software package called ADAPT-Mix available at https://github.com/dpark27/adapt_mix. Contact: noah.zaitlen@ucsf.edu PMID:26072481

How to Construct a Mixed Methods Research Design.

PubMed

Schoonenboom, Judith; Johnson, R Burke

2017-01-01

This article provides researchers with knowledge of how to design a high quality mixed methods research study. To design a mixed study, researchers must understand and carefully consider each of the dimensions of mixed methods design, and always keep an eye on the issue of validity. We explain the seven major design dimensions: purpose, theoretical drive, timing (simultaneity and dependency), point of integration, typological versus interactive design approaches, planned versus emergent design, and design complexity. There also are multiple secondary dimensions that need to be considered during the design process. We explain ten secondary dimensions of design to be considered for each research study. We also provide two case studies showing how the mixed designs were constructed.

An explicit mixed numerical method for mesoscale model

NASA Technical Reports Server (NTRS)

Hsu, H.-M.

1981-01-01

A mixed numerical method has been developed for mesoscale models. The technique consists of a forward difference scheme for time tendency terms, an upstream scheme for advective terms, and a central scheme for the other terms in a physical system. It is shown that the mixed method is conditionally stable and highly accurate for approximating the system of either shallow-water equations in one dimension or primitive equations in three dimensions. Since the technique is explicit and two time level, it conserves computer and programming resources.

Innovative Approaches to Fuel-Air Mixing and Combustion in Airbreathing Hypersonic Engines

NASA Astrophysics Data System (ADS)

MacLeod, C.

This paper describes some innovative methods for achieving enhanced fuel-air mixing and combustion in Scramjet-like spaceplane engines. A multimodal approach to the problem is discussed; this involves using several concurrent methods of forced mixing. The paper concentrates on Electromagnetic Activation (EMA) and Electrostatic Attraction as suitable techniques for this purpose - although several other potential methods are also discussed. Previously published empirical data is used to draw conclusions about the likely effectiveness of the system and possible engine topologies are outlined.

The Obstacles for the Teaching of 8th Grade TR History of Revolution and Kemalism Course According to the Constructivist Approach (An Example of Exploratory Sequential Mixed Method Design)

ERIC Educational Resources Information Center

Karademir, Yavuz; Demir, Selcuk Besir

2015-01-01

The aim of this study is to ascertain the problems social studies teachers face in the teaching of topics covered in 8th grade TRHRK Course. The study was conducted in line with explanatory sequential mixed method design, which is one of the mixed research method, was used. The study involves three phases. In the first step, exploratory process…

Octupole correlations in the 144Ba nucleus described with symmetry-conserving configuration-mixing calculations

NASA Astrophysics Data System (ADS)

Bernard, Rémi N.; Robledo, Luis M.; Rodríguez, Tomás R.

2016-06-01

We study the interplay of quadrupole and octupole degrees of freedom in the structure of the isotope 144Ba. A symmetry-conserving configuration-mixing method (SCCM) based on a Gogny energy density functional (EDF) has been used. The method includes particle number, parity, and angular momentum restoration as well as axial quadrupole and octupole shape mixing within the generator coordinate method. Predictions both for excitation energies and electromagnetic transition probabilities are in good agreement with the most recent experimental data.

Divergence preserving discrete surface integral methods for Maxwell's curl equations using non-orthogonal unstructured grids

NASA Technical Reports Server (NTRS)

Madsen, Niel K.

1992-01-01

Several new discrete surface integral (DSI) methods for solving Maxwell's equations in the time-domain are presented. These methods, which allow the use of general nonorthogonal mixed-polyhedral unstructured grids, are direct generalizations of the canonical staggered-grid finite difference method. These methods are conservative in that they locally preserve divergence or charge. Employing mixed polyhedral cells, (hexahedral, tetrahedral, etc.) these methods allow more accurate modeling of non-rectangular structures and objects because the traditional stair-stepped boundary approximations associated with the orthogonal grid based finite difference methods can be avoided. Numerical results demonstrating the accuracy of these new methods are presented.

Detection of malondialdehyde in processed meat products without interference from the ingredients.

PubMed

Jung, Samooel; Nam, Ki Chang; Jo, Cheorun

2016-10-15

Our aim was to develop a method for accurate quantification of malondialdehyde (MDA) in meat products. MDA content of uncured ground pork (Control); ground pork cured with sodium nitrite (Nitrite); and ground pork cured with sodium nitrite, sodium chloride, sodium pyrophosphate, maltodextrin, and a sausage seasoning (Mix) was measured by the 2-thiobarbituric acid (TBA) assay with MDA extraction by trichloroacetic acid (method A) and two high-performance liquid chromatography (HPLC) methods: i) HPLC separation of the MDA-dinitrophenyl hydrazine adduct (method B) and ii) HPLC separation of MDA (method C) after MDA extraction with acetonitrile. Methods A and B could not quantify MDA accurately in groups Nitrite and Mix. Nevertheless, MDA in groups Control, Nitrite, and Mix was accurately quantified by method C with good recovery. Therefore, direct MDA quantification by HPLC after MDA extraction with acetonitrile (method C) is useful for accurate measurement of MDA content in processed meat products. Copyright © 2016 Elsevier Ltd. All rights reserved.

Probe-specific mixed-model approach to detect copy number differences using multiplex ligation-dependent probe amplification (MLPA)

PubMed Central

González, Juan R; Carrasco, Josep L; Armengol, Lluís; Villatoro, Sergi; Jover, Lluís; Yasui, Yutaka; Estivill, Xavier

2008-01-01

Background MLPA method is a potentially useful semi-quantitative method to detect copy number alterations in targeted regions. In this paper, we propose a method for the normalization procedure based on a non-linear mixed-model, as well as a new approach for determining the statistical significance of altered probes based on linear mixed-model. This method establishes a threshold by using different tolerance intervals that accommodates the specific random error variability observed in each test sample. Results Through simulation studies we have shown that our proposed method outperforms two existing methods that are based on simple threshold rules or iterative regression. We have illustrated the method using a controlled MLPA assay in which targeted regions are variable in copy number in individuals suffering from different disorders such as Prader-Willi, DiGeorge or Autism showing the best performace. Conclusion Using the proposed mixed-model, we are able to determine thresholds to decide whether a region is altered. These threholds are specific for each individual, incorporating experimental variability, resulting in improved sensitivity and specificity as the examples with real data have revealed. PMID:18522760

Structural reanalysis via a mixed method. [using Taylor series for accuracy improvement

NASA Technical Reports Server (NTRS)

Noor, A. K.; Lowder, H. E.

1975-01-01

A study is made of the approximate structural reanalysis technique based on the use of Taylor series expansion of response variables in terms of design variables in conjunction with the mixed method. In addition, comparisons are made with two reanalysis techniques based on the displacement method. These techniques are the Taylor series expansion and the modified reduced basis. It is shown that the use of the reciprocals of the sizing variables as design variables (which is the natural choice in the mixed method) can result in a substantial improvement in the accuracy of the reanalysis technique. Numerical results are presented for a space truss structure.

Dual Formulations of Mixed Finite Element Methods with Applications

PubMed Central

Gillette, Andrew; Bajaj, Chandrajit

2011-01-01

Mixed finite element methods solve a PDE using two or more variables. The theory of Discrete Exterior Calculus explains why the degrees of freedom associated to the different variables should be stored on both primal and dual domain meshes with a discrete Hodge star used to transfer information between the meshes. We show through analysis and examples that the choice of discrete Hodge star is essential to the numerical stability of the method. Additionally, we define interpolation functions and discrete Hodge stars on dual meshes which can be used to create previously unconsidered mixed methods. Examples from magnetostatics and Darcy flow are examined in detail. PMID:21984841

Does Mixed Methods Research Matter to Understanding Childhood Well-Being?

ERIC Educational Resources Information Center

Jones, Nicola; Sumner, Andy

2009-01-01

There has been a rich debate in development studies on combining research methods in recent years. We explore the particular challenges and opportunities surrounding mixed methods approaches to childhood well-being. We argue that there are additional layers of complexity due to the distinctiveness of children's experiences of deprivation or…

[Application of the mixed programming with Labview and Matlab in biomedical signal analysis].

PubMed

Yu, Lu; Zhang, Yongde; Sha, Xianzheng

2011-01-01

This paper introduces the method of mixed programming with Labview and Matlab, and applies this method in a pulse wave pre-processing and feature detecting system. The method has been proved suitable, efficient and accurate, which has provided a new kind of approach for biomedical signal analysis.

A Review of Mixed Methods Research on Bullying and Peer Victimization in School

ERIC Educational Resources Information Center

Hong, Jun Sung; Espelage, Dorothy L.

2012-01-01

Recognizing the negative outcomes associated with experiences in bullying at school, educational researchers, school officials, and policy-makers have called for more rigorous research on bullying in school. Research on bullying behavior in school has primarily been examined using quantitative methods. Mixed methods research in the field of…

Illustrating a Mixed-Method Approach for Validating Culturally Specific Constructs

ERIC Educational Resources Information Center

Hitchcock, J.H.; Nastasi, B.K.; Dai, D.Y.; Newman, J.; Jayasena, A.; Bernstein-Moore, R.; Sarkar, S.; Varjas, K.

2005-01-01

The purpose of this article is to illustrate a mixed-method approach (i.e., combining qualitative and quantitative methods) for advancing the study of construct validation in cross-cultural research. The article offers a detailed illustration of the approach using the responses 612 Sri Lankan adolescents provided to an ethnographic survey. Such…

Pedagogical Strategies Used by Selected Leading Mixed Methodologists in Mixed Research Courses

ERIC Educational Resources Information Center

Frels, Rebecca K.; Onwuegbuzie, Anthony J.; Leech, Nancy L.; Collins, Kathleen M. T.

2014-01-01

The teaching of research methods is common across multiple fields in the social and educational sciences for establishing evidence-based practices and furthering the knowledge base through scholarship. Yet, specific to mixed methods, scant information exists as to how to approach teaching complex concepts for meaningful learning experiences. Thus,…

A Rationale for Mixed Methods (Integrative) Research Programmes in Education

ERIC Educational Resources Information Center

Niaz, Mansoor

2008-01-01

Recent research shows that research programmes (quantitative, qualitative and mixed) in education are not displaced (as suggested by Kuhn) but rather lead to integration. The objective of this study is to present a rationale for mixed methods (integrative) research programs based on contemporary philosophy of science (Lakatos, Giere, Cartwright,…

Mixed Methods for Mixed Reality: Understanding Users' Avatar Activities in Virtual Worlds

ERIC Educational Resources Information Center

Feldon, David F.; Kafai, Yasmin B.

2008-01-01

This paper examines the use of mixed methods for analyzing users' avatar-related activities in a virtual world. Server logs recorded keystroke-level activity for 595 participants over a six-month period in Whyville.net, an informal science website. Participants also completed surveys and participated in interviews regarding their experiences.…

Students awareness of learning styles and their perceptions to a mixed method approach for learning.

PubMed

Bhagat, Anumeha; Vyas, Rashmi; Singh, Tejinder

2015-08-01

Individualization of instructional method does not contribute significantly to learning outcomes although it is known that students have differing learning styles (LSs). Hence, in order to maximally enhance learning, one must try to use a mixed method approach. Our hypothesis was that awareness of preferred LS and motivation to incorporate multiple learning strategies might enhance learning outcomes. Our aim was to determine the impact of awareness of LS among medical undergraduates and motivating students to use mixed methods of learning. Before awareness lecture, LS preferences were determined using Visual, Aural, Read/Write, and Kinesthetic (VARK) questionnaire. Awareness of LS was assessed using a validated questionnaire. Through a lecture, students were oriented to various LSs, impact of LS on their performance, and benefit of using mixed method approach for learning. Subsequently, group discussions were organized. After 3 months, VARK preferences and awareness of LSs were reassessed. Student narratives were collected. Qualitative analysis of the data was done. There was a significant increase in the number of students who were aware of LS. The number of participants showing a change in VARK scores for various modalities of learning was also significant (P < 0.001). Thus, awareness of LSs motivated students to adapt other learning strategies and use mixed methods for learning.

Computing pKa Values with a Mixing Hamiltonian Quantum Mechanical/Molecular Mechanical Approach.

PubMed

Liu, Yang; Fan, Xiaoli; Jin, Yingdi; Hu, Xiangqian; Hu, Hao

2013-09-10

Accurate computation of the pKa value of a compound in solution is important but challenging. Here, a new mixing quantum mechanical/molecular mechanical (QM/MM) Hamiltonian method is developed to simulate the free-energy change associated with the protonation/deprotonation processes in solution. The mixing Hamiltonian method is designed for efficient quantum mechanical free-energy simulations by alchemically varying the nuclear potential, i.e., the nuclear charge of the transforming nucleus. In pKa calculation, the charge on the proton is varied in fraction between 0 and 1, corresponding to the fully deprotonated and protonated states, respectively. Inspired by the mixing potential QM/MM free energy simulation method developed previously [H. Hu and W. T. Yang, J. Chem. Phys. 2005, 123, 041102], this method succeeds many advantages of a large class of λ-coupled free-energy simulation methods and the linear combination of atomic potential approach. Theory and technique details of this method, along with the calculation results of the pKa of methanol and methanethiol molecules in aqueous solution, are reported. The results show satisfactory agreement with the experimental data.

Comparing team-based and mixed active-learning methods in an ambulatory care elective course.

PubMed

Zingone, Michelle M; Franks, Andrea S; Guirguis, Alexander B; George, Christa M; Howard-Thompson, Amanda; Heidel, Robert E

2010-11-10

To assess students' performance and perceptions of team-based and mixed active-learning methods in 2 ambulatory care elective courses, and to describe faculty members' perceptions of team-based learning. Using the 2 teaching methods, students' grades were compared. Students' perceptions were assessed through 2 anonymous course evaluation instruments. Faculty members who taught courses using the team-based learning method were surveyed regarding their impressions of team-based learning. The ambulatory care course was offered to 64 students using team-based learning (n = 37) and mixed active learning (n = 27) formats. The mean quality points earned were 3.7 (team-based learning) and 3.3 (mixed active learning), p < 0.001. Course evaluations for both courses were favorable. All faculty members who used the team-based learning method reported that they would consider using team-based learning in another course. Students were satisfied with both teaching methods; however, student grades were significantly higher in the team-based learning course. Faculty members recognized team-based learning as an effective teaching strategy for small-group active learning.

Comparative Performance of Engines Using a Carburetor, Manifold Injection, and Cylinder Injection

NASA Technical Reports Server (NTRS)

Schey, Oscar W; Clark, J Denny

1939-01-01

The comparative performance was determined of engines using three methods of mixing the fuel and the air: the use of a carburetor, manifold injection, and cylinder injection. The tests were made of a single-cylinder engine with a Wright 1820-G air-cooled cylinder. Each method of mixing the fuel and the air was investigated over a range of fuel-air ratios from 0.10 to the limit of stable operation and at engine speeds of 1,500 and 1,900 r.p.m. The comparative performance with a fuel-air ratio of 0.08 was investigated for speeds from 1,300 to 1,900 r.p.m. The results show that the power obtained with each method closely followed the volumetric efficiency; the power was therefore the highest with cylinder injection because this method had less manifold restriction. The values of minimum specific fuel consumption obtained with each method of mixing of fuel and air were the same. For the same engine and cooling conditions, the cylinder temperatures are the same regardless of the method used for mixing the fuel and the air.

Method for producing a compressed body of mix-powder for ceramic

NASA Technical Reports Server (NTRS)

Okawa, K.

1983-01-01

Under the invented method, a compressed body of mix powder for ceramic is produced by mixing and stirring several raw powder materials with mixing liquid such as water, and, in the process of sending the resulted viscous material pressurized at 5 kg/cm to 7 kg/cm, using 1.5 to 2 times the pressure to filter and dehydrate, adjusting the water content to 10 to 20%.

Mixed quantum/classical investigation of the photodissociation of NH3(Ã) and a practical method for maintaining zero-point energy in classical trajectories

NASA Astrophysics Data System (ADS)

Bonhommeau, David; Truhlar, Donald G.

2008-07-01

The photodissociation dynamics of ammonia upon excitation of the out-of-plane bending mode (mode ν2 with n2=0,…,6 quanta of vibration) in the à electronic state is investigated by means of several mixed quantum/classical methods, and the calculated final-state properties are compared to experiments. Five mixed quantum/classical methods are tested: one mean-field approach (the coherent switching with decay of mixing method), two surface-hopping methods [the fewest switches with time uncertainty (FSTU) and FSTU with stochastic decay (FSTU/SD) methods], and two surface-hopping methods with zero-point energy (ZPE) maintenance [the FSTU /SD+trajectory projection onto ZPE orbit (TRAPZ) and FSTU /SD+minimal TRAPZ (mTRAPZ) methods]. We found a qualitative difference between final NH2 internal energy distributions obtained for n2=0 and n2>1, as observed in experiments. Distributions obtained for n2=1 present an intermediate behavior between distributions obtained for smaller and larger n2 values. The dynamics is found to be highly electronically nonadiabatic with all these methods. NH2 internal energy distributions may have a negative energy tail when the ZPE is not maintained throughout the dynamics. The original TRAPZ method was designed to maintain ZPE in classical trajectories, but we find that it leads to unphysically high internal vibrational energies. The mTRAPZ method, which is new in this work and provides a general method for maintaining ZPE in either single-surface or multisurface trajectories, does not lead to unphysical results and is much less time consuming. The effect of maintaining ZPE in mixed quantum/classical dynamics is discussed in terms of agreement with experimental findings. The dynamics for n2=0 and n2=6 are also analyzed to reveal details not available from experiment, in particular, the time required for quenching of electronic excitation and the adiabatic energy gap and geometry at the time of quenching.

Mixed quantum/classical investigation of the photodissociation of NH3(A) and a practical method for maintaining zero-point energy in classical trajectories.

PubMed

Bonhommeau, David; Truhlar, Donald G

2008-07-07

The photodissociation dynamics of ammonia upon excitation of the out-of-plane bending mode (mode nu(2) with n(2)=0,[ellipsis (horizontal)],6 quanta of vibration) in the A electronic state is investigated by means of several mixed quantum/classical methods, and the calculated final-state properties are compared to experiments. Five mixed quantum/classical methods are tested: one mean-field approach (the coherent switching with decay of mixing method), two surface-hopping methods [the fewest switches with time uncertainty (FSTU) and FSTU with stochastic decay (FSTU/SD) methods], and two surface-hopping methods with zero-point energy (ZPE) maintenance [the FSTUSD+trajectory projection onto ZPE orbit (TRAPZ) and FSTUSD+minimal TRAPZ (mTRAPZ) methods]. We found a qualitative difference between final NH(2) internal energy distributions obtained for n(2)=0 and n(2)>1, as observed in experiments. Distributions obtained for n(2)=1 present an intermediate behavior between distributions obtained for smaller and larger n(2) values. The dynamics is found to be highly electronically nonadiabatic with all these methods. NH(2) internal energy distributions may have a negative energy tail when the ZPE is not maintained throughout the dynamics. The original TRAPZ method was designed to maintain ZPE in classical trajectories, but we find that it leads to unphysically high internal vibrational energies. The mTRAPZ method, which is new in this work and provides a general method for maintaining ZPE in either single-surface or multisurface trajectories, does not lead to unphysical results and is much less time consuming. The effect of maintaining ZPE in mixed quantum/classical dynamics is discussed in terms of agreement with experimental findings. The dynamics for n(2)=0 and n(2)=6 are also analyzed to reveal details not available from experiment, in particular, the time required for quenching of electronic excitation and the adiabatic energy gap and geometry at the time of quenching.

Development of a Hybrid RANS/LES Method for Turbulent Mixing Layers

NASA Technical Reports Server (NTRS)

Georgiadis, Nicholas J.; Alexander, J. Iwan D.; Reshotko, Eli

2001-01-01

Significant research has been underway for several years in NASA Glenn Research Center's nozzle branch to develop advanced computational methods for simulating turbulent flows in exhaust nozzles. The primary efforts of this research have concentrated on improving our ability to calculate the turbulent mixing layers that dominate flows both in the exhaust systems of modern-day aircraft and in those of hypersonic vehicles under development. As part of these efforts, a hybrid numerical method was recently developed to simulate such turbulent mixing layers. The method developed here is intended for configurations in which a dominant structural feature provides an unsteady mechanism to drive the turbulent development in the mixing layer. Interest in Large Eddy Simulation (LES) methods have increased in recent years, but applying an LES method to calculate the wide range of turbulent scales from small eddies in the wall-bounded regions to large eddies in the mixing region is not yet possible with current computers. As a result, the hybrid method developed here uses a Reynolds-averaged Navier-Stokes (RANS) procedure to calculate wall-bounded regions entering a mixing section and uses a LES procedure to calculate the mixing-dominated regions. A numerical technique was developed to enable the use of the hybrid RANS-LES method on stretched, non-Cartesian grids. With this technique, closure for the RANS equations is obtained by using the Cebeci-Smith algebraic turbulence model in conjunction with the wall-function approach of Ota and Goldberg. The LES equations are closed using the Smagorinsky subgrid scale model. Although the function of the Cebeci-Smith model to replace all of the turbulent stresses is quite different from that of the Smagorinsky subgrid model, which only replaces the small subgrid turbulent stresses, both are eddy viscosity models and both are derived at least in part from mixing-length theory. The similar formulation of these two models enables the RANS and LES equations to be solved with a single solution scheme and computational grid. The hybrid RANS-LES method has been applied to a benchmark compressible mixing layer experiment in which two isolated supersonic streams, separated by a splitter plate, provide the flows to a constant-area mixing section. Although the configuration is largely two dimensional in nature, three-dimensional calculations were found to be necessary to enable disturbances to develop in three spatial directions and to transition to turbulence. The flow in the initial part of the mixing section consists of a periodic vortex shedding downstream of the splitter plate trailing edge. This organized vortex shedding then rapidly transitions to a turbulent structure, which is very similar to the flow development observed in the experiments. Although the qualitative nature of the large-scale turbulent development in the entire mixing section is captured well by the LES part of the current hybrid method, further efforts are planned to directly calculate a greater portion of the turbulence spectrum and to limit the subgrid scale modeling to only the very small scales. This will be accomplished by the use of higher accuracy solution schemes and more powerful computers, measured both in speed and memory capabilities.

Using a mixed-methods design to examine nurse practitioner integration in British Columbia.

PubMed

Sangster-Gormley, Esther; Griffith, Janessa; Schreiber, Rita; Borycki, Elizabeth

2015-07-01

To discuss and provide examples of how mixed-methods research was used to evaluate the integration of nurse practitioners (NPs) into a Canadian province. Legislation enabling NPs to practise in British Columbia (BC) was enacted in 2005. This research evaluated the integration of NPs and their effect on the BC healthcare system. Data were collected using surveys, focus groups, participant interviews and case studies over three years. Data sources and methods were triangulated to determine how the findings addressed the research questions. The challenges and benefits of using the multiphase design are highlighted in the paper. The multiphase mixed-methods research design was selected because of its applicability to evaluation research. The design proved to be robust and flexible in answering research questions. As sub-studies within the multiphase design are often published separately, it can be difficult for researchers to find examples. This paper highlights ways that a multiphase mixed-methods design can be conducted for researchers unfamiliar with the process.

Rapid Contraceptive Uptake and Changing Method Mix With High Use of Long-Acting Reversible Contraceptives in Crisis-Affected Populations in Chad and the Democratic Republic of the Congo.

PubMed

Rattan, Jesse; Noznesky, Elizabeth; Curry, Dora Ward; Galavotti, Christine; Hwang, Shuyuan; Rodriguez, Mariela

2016-08-11

The global health community has recognized that expanding the contraceptive method mix is a programmatic imperative since (1) one-third of unintended pregnancies are due to method failure or discontinuation, and (2) the addition of a new method to the existing mix tends to increase total contraceptive use. Since July 2011, CARE has been implementing the Supporting Access to Family Planning and Post-Abortion Care (SAFPAC) initiative to increase the availability, quality, and use of contraception, with a particular focus on highly effective and long-acting reversible methods-intrauterine devices (IUDs) and implants-in crisis-affected settings in Chad and the Democratic Republic of the Congo (DRC). This initiative supports government health systems at primary and referral levels to provide a wide range of contraceptive services to people affected by conflict and/or displacement. Before the initiative, long-acting reversible methods were either unknown or unavailable in the intervention areas. However, as soon as trained providers were in place, we noted a dramatic and sustained increase in new users of all contraceptive methods, especially implants, with total new clients reaching 82,855, or 32% of the estimated number of women of reproductive age in the respective catchment areas in both countries, at the end of the fourth year. Demand for implants was very strong in the first 6 months after provider training. During this time, implants consistently accounted for more than 50% of the method mix, reaching as high as 89% in Chad and 74% in DRC. To ensure that all clients were getting the contraceptive method of their choice, we conducted a series of discussions and sought feedback from different stakeholders in order to modify program strategies. Key program modifications included more focused communication in mass media, community, and interpersonal channels about the benefits of IUDs while reinforcing the wide range of methods available and refresher training for providers on how to insert IUDs to strengthen their competence and confidence. Over time, we noted a gradual redistribution of the method mix in parallel with vigorous continued family planning uptake. This experience suggests that analyzing method mix can be helpful for designing program strategies and that expanding method choice can accelerate satisfying demand, especially in environments with high unmet need for contraception. © Rattan et al.

HIV quality report cards: impact of case-mix adjustment and statistical methods.

PubMed

Ohl, Michael E; Richardson, Kelly K; Goto, Michihiko; Vaughan-Sarrazin, Mary; Schweizer, Marin L; Perencevich, Eli N

2014-10-15

There will be increasing pressure to publicly report and rank the performance of healthcare systems on human immunodeficiency virus (HIV) quality measures. To inform discussion of public reporting, we evaluated the influence of case-mix adjustment when ranking individual care systems on the viral control quality measure. We used data from the Veterans Health Administration (VHA) HIV Clinical Case Registry and administrative databases to estimate case-mix adjusted viral control for 91 local systems caring for 12 368 patients. We compared results using 2 adjustment methods, the observed-to-expected estimator and the risk-standardized ratio. Overall, 10 913 patients (88.2%) achieved viral control (viral load ≤400 copies/mL). Prior to case-mix adjustment, system-level viral control ranged from 51% to 100%. Seventeen (19%) systems were labeled as low outliers (performance significantly below the overall mean) and 11 (12%) as high outliers. Adjustment for case mix (patient demographics, comorbidity, CD4 nadir, time on therapy, and income from VHA administrative databases) reduced the number of low outliers by approximately one-third, but results differed by method. The adjustment model had moderate discrimination (c statistic = 0.66), suggesting potential for unadjusted risk when using administrative data to measure case mix. Case-mix adjustment affects rankings of care systems on the viral control quality measure. Given the sensitivity of rankings to selection of case-mix adjustment methods-and potential for unadjusted risk when using variables limited to current administrative databases-the HIV care community should explore optimal methods for case-mix adjustment before moving forward with public reporting. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Unexpected but Most Welcome: Mixed Methods for the Validation and Revision of the Participatory Evaluation Measurement Instrument

ERIC Educational Resources Information Center

Daigneault, Pierre-Marc; Jacob, Steve

2014-01-01

Although combining methods is nothing new, more contributions about why and how to mix methods for validation purposes are needed. This article presents a case of validating the inferences drawn from the Participatory Evaluation Measurement Instrument, an instrument that purports to measure stakeholder participation in evaluation. Although the…

What Are the Teaching Responsibilities of Being a Teacher?

ERIC Educational Resources Information Center

Gunduz, Mevlut

2016-01-01

The aim of this paper is to find out what kind of learning responsibility has been formed on the learner when a teacher performs his/her responsibility. The paper uses mixed-method research design. In mixed-method, more reliable and pluralist data can be obtained by using both qualitative and quantitative methods. For the qualitative aspect, one…

Method of forming particulate materials for thin-film solar cells

DOEpatents

Eberspacher, Chris; Pauls, Karen Lea

2004-11-23

A method for preparing particulate materials useful in fabricating thin-film solar cells is disclosed. Particulate materials is prepared by the method include for example materials comprising copper and indium and/or gallium in the form of single-phase, mixed-metal oxide particulates; multi-phase, mixed-metal particulates comprising a metal oxide; and multinary metal particulates.

Evaluating the Impact of an Urban Comprehensive School Reform: An Illustration of the Need for Mixed Methods

ERIC Educational Resources Information Center

Sondergeld, Toni A.; Koskey, Kristin L. K.

2011-01-01

An abundance of comprehensive school reform (CSR) literature exists illustrating CSRs are effective in improving student outcomes. However, much of this research reports on top-down reforms, focuses on academic outcomes, and uses quantitative methods alone. Many educational researchers have argued for the use of mixed methods for providing a…

The Effect of Coach Expectations on Female Athletes' Motivation to Play: A Mixed Methods Approach

ERIC Educational Resources Information Center

Buning, Megan Matthews

2013-01-01

This concurrent, embedded mixed methods study used predominantly quantitative analyses to examine coach expectations and behaviors on female athletes' intrinsic motivation to play softball. Qualitative methods in the form of structured, open-ended questions were used to enhance the data by examining athletes' perceptions of coaching…

On Mixed Methods: Approaches to Language and Literacy Research (An NCRLL Volume). Language & Literacy Series (NCRLL Collection)

ERIC Educational Resources Information Center

Calfee, Robert; Sperling, Melanie

2010-01-01

This book examines the use of mixed methods for conducting language and literacy research, defining how and why this approach is successful for solving problems and clarifying issues that researchers encounter. Using research findings, the authors explore how an intermingling of multiple methods expands the possibilities of observation and…

Adolescent (Mis)Perceptions about Nicotine Addiction: Results from a Mixed-Methods Study

ERIC Educational Resources Information Center

Roditis, Maria; Lee, Joann; Halpern-Felsher, Bonnie L.

2016-01-01

Purpose: Despite evidence that adolescents become addicted to nicotine even after limited use, adolescents believe they can experiment with or smoke cigarettes for a few years and easily quit. The goal of this study was to examine adolescents' understanding of the definition and process of nicotine addiction using a mixed-methods approach. Method:…

A Mixed-Methods Study Investigating the Relationship between Media Multitasking Orientation and Grade Point Average

ERIC Educational Resources Information Center

Lee, Jennifer

2012-01-01

The intent of this study was to examine the relationship between media multitasking orientation and grade point average. The study utilized a mixed-methods approach to investigate the research questions. In the quantitative section of the study, the primary method of statistical analyses was multiple regression. The independent variables for the…

The Virginia method of determining the cement content of freshly mixed cement-soil mixtures : a manual prepared for the use of the Virginia Dept. of Highways.

DOT National Transportation Integrated Search

1971-01-01

This manual describes a new method developed by the author, based on ASTM Method D2901, for determining the cement content of freshly mixed soil cement. The manual contains information on apparatus, reagents, procedures, source of equipment and reage...

A Mixed Methods Content Analysis of the Research Literature in Science Education

ERIC Educational Resources Information Center

Schram, Asta B.

2014-01-01

In recent years, more and more researchers in science education have been turning to the practice of combining qualitative and quantitative methods in the same study. This approach of using mixed methods creates possibilities to study the various issues that science educators encounter in more depth. In this content analysis, I evaluated 18…

Indiscriminate Friendliness in Children Adopted from China to the United States: A Mixed Methods Study

ERIC Educational Resources Information Center

Liu, Yanhong; Li, Dan; Xu, Yanqing

2017-01-01

Indiscriminate friendliness (IF) is a prominent issue with children adopted from China to the United States. Through a mixed methods design, the authors explored four Chinese adoptees' experiences of IF within their real-life context, investigated potential factors associated with IF, and examined the IF-attachment relationship. This mixed methods…

The Multilevel Mixed Intact Group Analysis: A Mixed Method to Seek, Detect, Describe, and Explain Differences Among Intact Groups

ERIC Educational Resources Information Center

Schoonenboom, Judith

2016-01-01

Educational innovations often involve intact subgroups, such as school classes or university departments. In small-scale educational evaluation research, typically involving 1 to 20 subgroups, differences among these subgroups are often neglected. This article presents a mixed method from a qualitative perspective, in which differences among…

Estimating growth and yield of mixed stands

Treesearch

Stephen R. Shifley; Burnell C. Fischer

1989-01-01

A mixed stand is defined as one in which no single species comprises more than 80 percent of the stocking. The growth estimation methods described below can be used not only in mixed stands but in almost any stand, regardless of species composition, age structure, or size structure. The methods described are necessary to accommodate the complex species mixtures and...

Finite elements and finite differences for transonic flow calculations

NASA Technical Reports Server (NTRS)

Hafez, M. M.; Murman, E. M.; Wellford, L. C.

1978-01-01

The paper reviews the chief finite difference and finite element techniques used for numerical solution of nonlinear mixed elliptic-hyperbolic equations governing transonic flow. The forms of the governing equations for unsteady two-dimensional transonic flow considered are the Euler equation, the full potential equation in both conservative and nonconservative form, the transonic small-disturbance equation in both conservative and nonconservative form, and the hodograph equations for the small-disturbance case and the full-potential case. Finite difference methods considered include time-dependent methods, relaxation methods, semidirect methods, and hybrid methods. Finite element methods include finite element Lax-Wendroff schemes, implicit Galerkin method, mixed variational principles, dual iterative procedures, optimal control methods and least squares.

Direct numerical simulations of a reacting turbulent mixing layer by a pseudospectral-spectral element method

NASA Technical Reports Server (NTRS)

Mcmurtry, Patrick A.; Givi, Peyman

1992-01-01

An account is given of the implementation of the spectral-element technique for simulating a chemically reacting, spatially developing turbulent mixing layer. Attention is given to experimental and numerical studies that have investigated the development, evolution, and mixing characteristics of shear flows. A mathematical formulation is presented of the physical configuration of the spatially developing reacting mixing layer, in conjunction with a detailed representation of the spectral-element method's application to the numerical simulation of mixing layers. Results from 2D and 3D calculations of chemically reacting mixing layers are given.

Bioactivity of CaSiO3/poly-lactic acid (PLA) composites prepared by various surface loading methods of CaSiO3 powder.

PubMed

Okada, Kiyoshi; Hasegawa, Fumikazu; Kameshima, Yoshikazu; Nakajima, Akira

2007-05-01

Mixing bioactive ceramic powders with polymers is an effective method for generating bioactivity to the polymer-matrix composites but it is necessary to incorporate up to 40 vol% of bioactive ceramic powder. However, such a high mixing ratio offsets the advantages of the flexibility and formability of polymer matrix and it would be highly advantageous to lower the mixing ratio. Since surface loading of ceramic powders in the polymer is thought to be an effective way of reducing the mixing ratio of the ceramic powder while maintaining bioactive activity, CaSiO(3)/poly-lactic acid (PLA) composites were prepared by three methods; (1) casting, (2) spin coating and (3) hot pressing. In methods (1) and (2), a suspension was prepared by dissolving PLA in chloroform and dispersing CaSiO(3) powder in it. The suspension was cast and dried to form a film in the case of method (1) while it was spin-coated on a PLA substrate in method (2). In method (3), CaSiO(3) powder was surface loaded on to a PLA substrate by hot pressing. The bioactivity of these samples was investigated in vitro using simulated body fluid (SBF). Apatite formation was not observed in the samples prepared by method (1) but some apatite formation was achieved by mixing polyethylene glycol (PEG) with the PLA, producing a porous polymer matrix. In method (2), apatite was clearly observed after soaking for 7 days. Enhanced apatite formation was observed in method (3), the thickness of the resulting apatite layers becoming about 20 microm after soaking for 14 days. Since the amount of CaSiO(3) powder used in these samples was only

Bioactivity of CaSiO3/poly-lactic acid (PLA) composites prepared by various surface loading methods of CaSiO3 powder.

PubMed

Okada, Kiyoshi; Hasegawa, Fumikazu; Kameshima, Yoshikazu; Nakajima, Akira

2007-08-01

Mixing bioactive ceramic powders with polymers is an effective method for generating bioactivity to the polymer-matrix composites but it is necessary to incorporate up to 40 vol% of bioactive ceramic powder. However, such a high mixing ratio offsets the advantages of the flexibility and formability of polymer matrix and it would be highly advantageous to lower the mixing ratio. Since surface loading of ceramic powders in the polymer is thought to be an effective way of reducing the mixing ratio of the ceramic powder while maintaining bioactive activity, CaSiO(3)/poly-lactic acid (PLA) composites were prepared by three methods; (1) casting, (2) spin coating and (3) hot pressing. In methods (1) and (2), a suspension was prepared by dissolving PLA in chloroform and dispersing CaSiO(3) powder in it. The suspension was cast and dried to form a film in the case of method (1) while it was spin-coated on a PLA substrate in method (2). In method (3), CaSiO(3) powder was surface loaded on to a PLA substrate by hot-pressing. The bioactivity of these samples was investigated in vitro using simulated body fluid (SBF). Apatite formation was not observed in the samples prepared by method (1) but some apatite formation was achieved by mixing polyethylene glycol (PEG) with the PLA, producing a porous polymer matrix. In method (2), apatite was clearly observed after soaking for 7 days. Enhanced apatite formation was observed in method (3), the thickness of the resulting apatite layers becoming about 20 microm after soaking for 14 days. Since the amount of CaSiO(3) powder used in these samples was only < or =0.4 vol%, it is concluded that this preparation method is very effective in generating bioactivity in polymer-matrix composites by loading with only very small amounts of ceramic powder.

Advantages and pitfalls in the application of mixed-model association methods.

PubMed

Yang, Jian; Zaitlen, Noah A; Goddard, Michael E; Visscher, Peter M; Price, Alkes L

2014-02-01

Mixed linear models are emerging as a method of choice for conducting genetic association studies in humans and other organisms. The advantages of the mixed-linear-model association (MLMA) method include the prevention of false positive associations due to population or relatedness structure and an increase in power obtained through the application of a correction that is specific to this structure. An underappreciated point is that MLMA can also increase power in studies without sample structure by implicitly conditioning on associated loci other than the candidate locus. Numerous variations on the standard MLMA approach have recently been published, with a focus on reducing computational cost. These advances provide researchers applying MLMA methods with many options to choose from, but we caution that MLMA methods are still subject to potential pitfalls. Here we describe and quantify the advantages and pitfalls of MLMA methods as a function of study design and provide recommendations for the application of these methods in practical settings.

Scale-Up of Lubricant Mixing Process by Using V-Type Blender Based on Discrete Element Method.

PubMed

Horibe, Masashi; Sonoda, Ryoichi; Watano, Satoru

2018-01-01

A method for scale-up of a lubricant mixing process in a V-type blender was proposed. Magnesium stearate was used for the lubricant, and the lubricant mixing experiment was conducted using three scales of V-type blenders (1.45, 21 and 130 L) under the same fill level and Froude (Fr) number. However, the properties of lubricated mixtures and tablets could not correspond with the mixing time or the total revolution number. To find the optimum scale-up factor, discrete element method (DEM) simulations of three scales of V-type blender mixing were conducted, and the total travel distance of particles under the different scales was calculated. The properties of the lubricated mixture and tablets obtained from the scale-up experiment were well correlated with the mixing time determined by the total travel distance. It was found that a scale-up simulation based on the travel distance of particles is valid for the lubricant mixing scale-up processes.

Analysis of injury types for mixed martial arts athletes

PubMed Central

Ji, MinJoon

2016-01-01

[Purpose] The purpose of the present study was to examine the types of injuries associated with mixed martial arts and their location in order to provide substantial information to help reduce the risk of these injuries during mixed martial arts. [Subjects and Methods] Data were collected from 455 mixed martial arts athletes who practiced mixed martial arts or who participated in mixed martial arts competitions in the Seoul Metropolitan City and Gyeongnam Province of Korea between June 3, 2015, and November 6, 2015. Questionnaires were used to collect the data. The convenience sampling method was used, based on the non-probability sampling extraction method. [Results] The arm, neck, and head were the most frequent locations of the injuries; and lacerations, concussions, and contusions were the most frequently diagnosed types of injuries in the mixed martial arts athletes in this study. [Conclusion] Reducing the risk of injury by establishing an alert system and preventing critical injuries by incorporating safety measures are important. PMID:27313367

Analysis of injury types for mixed martial arts athletes.

PubMed

Ji, MinJoon

2016-05-01

[Purpose] The purpose of the present study was to examine the types of injuries associated with mixed martial arts and their location in order to provide substantial information to help reduce the risk of these injuries during mixed martial arts. [Subjects and Methods] Data were collected from 455 mixed martial arts athletes who practiced mixed martial arts or who participated in mixed martial arts competitions in the Seoul Metropolitan City and Gyeongnam Province of Korea between June 3, 2015, and November 6, 2015. Questionnaires were used to collect the data. The convenience sampling method was used, based on the non-probability sampling extraction method. [Results] The arm, neck, and head were the most frequent locations of the injuries; and lacerations, concussions, and contusions were the most frequently diagnosed types of injuries in the mixed martial arts athletes in this study. [Conclusion] Reducing the risk of injury by establishing an alert system and preventing critical injuries by incorporating safety measures are important.

Improved methods of vibration analysis of pretwisted, airfoil blades

NASA Technical Reports Server (NTRS)

Subrahmanyam, K. B.; Kaza, K. R. V.

1984-01-01

Vibration analysis of pretwisted blades of asymmetric airfoil cross section is performed by using two mixed variational approaches. Numerical results obtained from these two methods are compared to those obtained from an improved finite difference method and also to those given by the ordinary finite difference method. The relative merits, convergence properties and accuracies of all four methods are studied and discussed. The effects of asymmetry and pretwist on natural frequencies and mode shapes are investigated. The improved finite difference method is shown to be far superior to the conventional finite difference method in several respects. Close lower bound solutions are provided by the improved finite difference method for untwisted blades with a relatively coarse mesh while the mixed methods have not indicated any specific bound.

Rapid Contraceptive Uptake and Changing Method Mix With High Use of Long-Acting Reversible Contraceptives in Crisis-Affected Populations in Chad and the Democratic Republic of the Congo

PubMed Central

Rattan, Jesse; Noznesky, Elizabeth; Curry, Dora Ward; Galavotti, Christine; Hwang, Shuyuan; Rodriguez, Mariela

2016-01-01

ABSTRACT The global health community has recognized that expanding the contraceptive method mix is a programmatic imperative since (1) one-third of unintended pregnancies are due to method failure or discontinuation, and (2) the addition of a new method to the existing mix tends to increase total contraceptive use. Since July 2011, CARE has been implementing the Supporting Access to Family Planning and Post-Abortion Care (SAFPAC) initiative to increase the availability, quality, and use of contraception, with a particular focus on highly effective and long-acting reversible methods—intrauterine devices (IUDs) and implants—in crisis-affected settings in Chad and the Democratic Republic of the Congo (DRC). This initiative supports government health systems at primary and referral levels to provide a wide range of contraceptive services to people affected by conflict and/or displacement. Before the initiative, long-acting reversible methods were either unknown or unavailable in the intervention areas. However, as soon as trained providers were in place, we noted a dramatic and sustained increase in new users of all contraceptive methods, especially implants, with total new clients reaching 82,855, or 32% of the estimated number of women of reproductive age in the respective catchment areas in both countries, at the end of the fourth year. Demand for implants was very strong in the first 6 months after provider training. During this time, implants consistently accounted for more than 50% of the method mix, reaching as high as 89% in Chad and 74% in DRC. To ensure that all clients were getting the contraceptive method of their choice, we conducted a series of discussions and sought feedback from different stakeholders in order to modify program strategies. Key program modifications included more focused communication in mass media, community, and interpersonal channels about the benefits of IUDs while reinforcing the wide range of methods available and refresher training for providers on how to insert IUDs to strengthen their competence and confidence. Over time, we noted a gradual redistribution of the method mix in parallel with vigorous continued family planning uptake. This experience suggests that analyzing method mix can be helpful for designing program strategies and that expanding method choice can accelerate satisfying demand, especially in environments with high unmet need for contraception. PMID:27540125

Method for stabilizing low-level mixed wastes at room temperature

DOEpatents

Wagh, A.S.; Singh, D.

1997-07-08

A method to stabilize solid and liquid waste at room temperature is provided comprising combining solid waste with a starter oxide to obtain a powder, contacting the powder with an acid solution to create a slurry, said acid solution containing the liquid waste, shaping the now-mixed slurry into a predetermined form, and allowing the now-formed slurry to set. The invention also provides for a method to encapsulate and stabilize waste containing cesium comprising combining the waste with Zr(OH){sub 4} to create a solid-phase mixture, mixing phosphoric acid with the solid-phase mixture to create a slurry, subjecting the slurry to pressure; and allowing the now pressurized slurry to set. Lastly, the invention provides for a method to stabilize liquid waste, comprising supplying a powder containing magnesium, sodium and phosphate in predetermined proportions, mixing said powder with the liquid waste, such as tritium, and allowing the resulting slurry to set. 4 figs.

Method for stabilizing low-level mixed wastes at room temperature

DOEpatents

Wagh, Arun S.; Singh, Dileep

1997-01-01

A method to stabilize solid and liquid waste at room temperature is provided comprising combining solid waste with a starter oxide to obtain a powder, contacting the powder with an acid solution to create a slurry, said acid solution containing the liquid waste, shaping the now-mixed slurry into a predetermined form, and allowing the now-formed slurry to set. The invention also provides for a method to encapsulate and stabilize waste containing cesium comprising combining the waste with Zr(OH).sub.4 to create a solid-phase mixture, mixing phosphoric acid with the solid-phase mixture to create a slurry, subjecting the slurry to pressure; and allowing the now pressurized slurry to set. Lastly, the invention provides for a method to stabilize liquid waste, comprising supplying a powder containing magnesium, sodium and phosphate in predetermined proportions, mixing said powder with the liquid waste, such as tritium, and allowing the resulting slurry to set.

Combined qualitative and quantitative research designs.

PubMed

Seymour, Jane

2012-12-01

Mixed methods research designs have been recognized as important in addressing complexity and are recommended particularly in the development and evaluation of complex interventions. This article reports a review of studies in palliative care published between 2010 and March 2012 that combine qualitative and quantitative approaches. A synthesis of approaches to mixed methods research taken in 28 examples of published research studies of relevance to palliative and supportive care is provided, using a typology based on a classic categorization put forward in 1992. Mixed-method studies are becoming more frequently employed in palliative care research and resonate with the complexity of the palliative care endeavour. Undertaking mixed methods research requires a sophisticated understanding of the research process and recognition of some of the underlying complexities encountered when working with different traditions and perspectives on issues of: sampling, validity, reliability and rigour, different sources of data and different data collection and analysis techniques.

Adaptive mixed finite element methods for Darcy flow in fractured porous media

NASA Astrophysics Data System (ADS)

Chen, Huangxin; Salama, Amgad; Sun, Shuyu

2016-10-01

In this paper, we propose adaptive mixed finite element methods for simulating the single-phase Darcy flow in two-dimensional fractured porous media. The reduced model that we use for the simulation is a discrete fracture model coupling Darcy flows in the matrix and the fractures, and the fractures are modeled by one-dimensional entities. The Raviart-Thomas mixed finite element methods are utilized for the solution of the coupled Darcy flows in the matrix and the fractures. In order to improve the efficiency of the simulation, we use adaptive mixed finite element methods based on novel residual-based a posteriori error estimators. In addition, we develop an efficient upscaling algorithm to compute the effective permeability of the fractured porous media. Several interesting examples of Darcy flow in the fractured porous media are presented to demonstrate the robustness of the algorithm.

An adaptive image sparse reconstruction method combined with nonlocal similarity and cosparsity for mixed Gaussian-Poisson noise removal

NASA Astrophysics Data System (ADS)

Chen, Yong-fei; Gao, Hong-xia; Wu, Zi-ling; Kang, Hui

2018-01-01

Compressed sensing (CS) has achieved great success in single noise removal. However, it cannot restore the images contaminated with mixed noise efficiently. This paper introduces nonlocal similarity and cosparsity inspired by compressed sensing to overcome the difficulties in mixed noise removal, in which nonlocal similarity explores the signal sparsity from similar patches, and cosparsity assumes that the signal is sparse after a possibly redundant transform. Meanwhile, an adaptive scheme is designed to keep the balance between mixed noise removal and detail preservation based on local variance. Finally, IRLSM and RACoSaMP are adopted to solve the objective function. Experimental results demonstrate that the proposed method is superior to conventional CS methods, like K-SVD and state-of-art method nonlocally centralized sparse representation (NCSR), in terms of both visual results and quantitative measures.

Application of mixed-methods design in community-engaged research: Lessons learned from an evidence-based intervention for Latinos with chronic illness and minor depression.

PubMed

Aguado Loi, Claudia X; Alfonso, Moya L; Chan, Isabella; Anderson, Kelsey; Tyson, Dinorah Dina Martinez; Gonzales, Junius; Corvin, Jaime

2017-08-01

The purpose of this paper is to share lessons learned from a collaborative, community-informed mixed-methods approach to adapting an evidence-based intervention to meet the needs of Latinos with chronic disease and minor depression and their family members. Mixed-methods informed by community-based participatory research (CBPR) were employed to triangulate multiple stakeholders' perceptions of facilitators and barriers of implementing the adapted intervention in community settings. Community partners provided an insider perspective to overcome methodological challenges. The study's community informed mixed-methods: research approach offered advantages to a single research methodology by expanding or confirming research findings and engaging multiple stakeholders in data collection. This approach also allowed community partners to collaborate with academic partners in key research decisions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Levels of reconstruction as complementarity in mixed methods research: a social theory-based conceptual framework for integrating qualitative and quantitative research.

PubMed

Carroll, Linda J; Rothe, J Peter

2010-09-01

Like other areas of health research, there has been increasing use of qualitative methods to study public health problems such as injuries and injury prevention. Likewise, the integration of qualitative and quantitative research (mixed-methods) is beginning to assume a more prominent role in public health studies. Likewise, using mixed-methods has great potential for gaining a broad and comprehensive understanding of injuries and their prevention. However, qualitative and quantitative research methods are based on two inherently different paradigms, and their integration requires a conceptual framework that permits the unity of these two methods. We present a theory-driven framework for viewing qualitative and quantitative research, which enables us to integrate them in a conceptually sound and useful manner. This framework has its foundation within the philosophical concept of complementarity, as espoused in the physical and social sciences, and draws on Bergson's metaphysical work on the 'ways of knowing'. Through understanding how data are constructed and reconstructed, and the different levels of meaning that can be ascribed to qualitative and quantitative findings, we can use a mixed-methods approach to gain a conceptually sound, holistic knowledge about injury phenomena that will enhance our development of relevant and successful interventions.

Interdisciplinary mixed methods research with structurally vulnerable populations: case studies of injection drug users in San Francisco.

PubMed

Lopez, Andrea M; Bourgois, Philippe; Wenger, Lynn D; Lorvick, Jennifer; Martinez, Alexis N; Kral, Alex H

2013-03-01

Research with injection drug users (IDUs) benefits from interdisciplinary theoretical and methodological innovation because drug use is illegal, socially sanctioned and often hidden. Despite the increasing visibility of interdisciplinary, mixed methods research projects with IDUs, qualitative components are often subordinated to quantitative approaches and page restrictions in top addiction journals limit detailed reports of complex data collection and analysis logistics, thus minimizing the fuller scientific potential of genuine mixed methods. We present the methodological logistics and conceptual approaches of four mixed-methods research projects that our interdisciplinary team conducted in San Francisco with IDUs over the past two decades. These projects include combinations of participant-observation ethnography, in-depth qualitative interviewing, epidemiological surveys, photo-documentation, and geographic mapping. We adapted Greene et al.'s framework for combining methods in a single research project through: data triangulation, methodological complementarity, methodological initiation, and methodological expansion. We argue that: (1) flexible and self-reflexive methodological procedures allowed us to seize strategic opportunities to document unexpected and sometimes contradictory findings as they emerged to generate new research questions, (2) iteratively mixing methods increased the scope, reliability, and generalizability of our data, and (3) interdisciplinary collaboration contributed to a scientific "value added" that allowed for more robust theoretical and practical findings about drug use and risk-taking. Copyright © 2013 Elsevier B.V. All rights reserved.

Interdisciplinary Mixed Methods Research with Structurally Vulnerable Populations: Case Studies of Injection Drug Users in San Francisco

PubMed Central

Lopez, Andrea; Bourgois, Philippe; Wenger, Lynn; Lorvick, Jennifer; Martinez, Alexis; Kral, Alex H.

2013-01-01

Research with injection drug users (IDUs) benefits from interdisciplinary theoretical and methodological innovation because drug use is illegal, socially sanctioned and often hidden. Despite the increasing visibility of interdisciplinary, mixed methods research projects with IDUs, qualitative components are often subordinated to quantitative approaches and page restrictions in top addiction journals limit detailed reports of complex data collection and analysis logistics, thus minimizing the fuller scientific potential of genuine mixed methods. We present the methodological logistics and conceptual approaches of four mixed-methods research projects that our interdisciplinary team conducted in San Francisco with IDUs over the past two decades. These projects include combinations of participant-observation ethnography, in-depth qualitative interviewing, epidemiological surveys, photo-documentation, and geographic mapping. We adapted Greene et al.’s framework for combining methods in a single research project through: data triangulation, methodological complementarity, methodological initiation, and methodological expansion. We argue that: (1) flexible and self-reflexive methodological procedures allowed us to seize strategic opportunities to document unexpected and sometimes contradictory findings as they emerged to generate new research questions, (2) iteratively mixing methods increased the scope, reliability, and generalizability of our data, and (3) interdisciplinary collaboration contributed to a scientific “value added” that allowed for more robust theoretical and practical findings about drug use and risk-taking. PMID:23312109

A Study of Interactions between Mixing and Chemical Reaction Using the Rate-Controlled Constrained-Equilibrium Method

NASA Astrophysics Data System (ADS)

Hadi, Fatemeh; Janbozorgi, Mohammad; Sheikhi, M. Reza H.; Metghalchi, Hameed

2016-10-01

The rate-controlled constrained-equilibrium (RCCE) method is employed to study the interactions between mixing and chemical reaction. Considering that mixing can influence the RCCE state, the key objective is to assess the accuracy and numerical performance of the method in simulations involving both reaction and mixing. The RCCE formulation includes rate equations for constraint potentials, density and temperature, which allows taking account of mixing alongside chemical reaction without splitting. The RCCE is a dimension reduction method for chemical kinetics based on thermodynamics laws. It describes the time evolution of reacting systems using a series of constrained-equilibrium states determined by RCCE constraints. The full chemical composition at each state is obtained by maximizing the entropy subject to the instantaneous values of the constraints. The RCCE is applied to a spatially homogeneous constant pressure partially stirred reactor (PaSR) involving methane combustion in oxygen. Simulations are carried out over a wide range of initial temperatures and equivalence ratios. The chemical kinetics, comprised of 29 species and 133 reaction steps, is represented by 12 RCCE constraints. The RCCE predictions are compared with those obtained by direct integration of the same kinetics, termed detailed kinetics model (DKM). The RCCE shows accurate prediction of combustion in PaSR with different mixing intensities. The method also demonstrates reduced numerical stiffness and overall computational cost compared to DKM.

A flexible layout design method for passive micromixers.

PubMed

Deng, Yongbo; Liu, Zhenyu; Zhang, Ping; Liu, Yongshun; Gao, Qingyong; Wu, Yihui

2012-10-01

This paper discusses a flexible layout design method of passive micromixers based on the topology optimization of fluidic flows. Being different from the trial and error method, this method obtains the detailed layout of a passive micromixer according to the desired mixing performance by solving a topology optimization problem. Therefore, the dependence on the experience of the designer is weaken, when this method is used to design a passive micromixer with acceptable mixing performance. Several design disciplines for the passive micromixers are considered to demonstrate the flexibility of the layout design method for passive micromixers. These design disciplines include the approximation of the real 3D micromixer, the manufacturing feasibility, the spacial periodic design, and effects of the Péclet number and Reynolds number on the designs obtained by this layout design method. The capability of this design method is validated by several comparisons performed between the obtained layouts and the optimized designs in the recently published literatures, where the values of the mixing measurement is improved up to 40.4% for one cycle of the micromixer.

How to test validity in orthodontic research: a mixed dentition analysis example.

PubMed

Donatelli, Richard E; Lee, Shin-Jae

2015-02-01

The data used to test the validity of a prediction method should be different from the data used to generate the prediction model. In this study, we explored whether an independent data set is mandatory for testing the validity of a new prediction method and how validity can be tested without independent new data. Several validation methods were compared in an example using the data from a mixed dentition analysis with a regression model. The validation errors of real mixed dentition analysis data and simulation data were analyzed for increasingly large data sets. The validation results of both the real and the simulation studies demonstrated that the leave-1-out cross-validation method had the smallest errors. The largest errors occurred in the traditional simple validation method. The differences between the validation methods diminished as the sample size increased. The leave-1-out cross-validation method seems to be an optimal validation method for improving the prediction accuracy in a data set with limited sample sizes. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

An Examination of Diversity within Three Southeastern Academic Libraries: A Mixed-Methods, Multi-Site Study

ERIC Educational Resources Information Center

Shaffer, Christopher A.

2014-01-01

The purpose of this study was to determine the extent to which three academic libraries in the Southeastern United States could be considered diverse. This was a multi-site, mixed methods study. It examined the climate and culture of the libraries, which was assessed through two methods; the first, through survey responses from full-time faculty…

Microprobes aluminosilicate ceramic membranes

DOEpatents

Anderson, Marc A.; Sheng, Guangyao

1993-01-01

Methods have been developed to make mixed alumina-silicate and aluminosilicate particulate microporous ceramic membranes. One method involves the making of separate alumina and silica sols which are then mixed. Another method involves the creation of a combined sol with aluminosilicate particles. The resulting combined alumina and silica membranes have high surface area, a very small pore size, and a very good temperature stability.

The Employers' Perspective on Barriers and Facilitators to Employment of People with Intellectual Disability: A Differential Mixed-Method Approach

ERIC Educational Resources Information Center

Kocman, Andreas; Fischer, Linda; Weber, Germain

2018-01-01

Background: Obtaining employment is among the most important ambitions of people with intellectual disability. Progress towards comprehensive inclusive employment is hampered by numerous barriers. Limited research is available on these barriers and strategies to overcome them. Method: A mixed method approach in a sample of 30 HR-managers was used…

A Health Website Recommendation from Gold Coast General Practitioners to Their Patients: A Mixed Method Approach

ERIC Educational Resources Information Center

Usher, Wayne

2011-01-01

Introduction: To identify health website recommendation trends by Gold Coast (Australia) general practitioners (GPs) to their patients. Method: A mixed method approach to data collection and analysis was employed. Quantitative data were collected using a prepaid postal survey, consisting of 17 questions, mailed to 250 (61 per cent) of 410 GPs on…

Assessing Change in the Teaching Practice of Faculty in a Faculty Development Program for Primary Care Physicians: Toward a Mixed Method Evaluation Approach.

ERIC Educational Resources Information Center

Pinheiro, Sandro O.; Rohrer, Jonathan D.; Heimann, C. F. Larry

This paper describes a mixed method evaluation study that was developed to assess faculty teaching behavior change in a faculty development fellowship program for community-based hospital faculty. Principles of adult learning were taught to faculty participants over the fellowship period. These included instruction in teaching methods, group…

Scale Development and Initial Tests of the Multidimensional Complex Adaptive Leadership Scale for School Principals: An Exploratory Mixed Method Study

ERIC Educational Resources Information Center

Özen, Hamit; Turan, Selahattin

2017-01-01

This study was designed to develop the scale of the Complex Adaptive Leadership for School Principals (CAL-SP) and examine its psychometric properties. This was an exploratory mixed method research design (ES-MMD). Both qualitative and quantitative methods were used to develop and assess psychometric properties of the questionnaire. This study…

Telling It All : A Story of Women's Social Capital Using a Mixed Methods Approach

ERIC Educational Resources Information Center

Hodgkin, Suzanne

2008-01-01

The aim of this article is to demonstrate how quantitative and qualitative methods can be us together in feminist research. Despite an increasing number of texts and journal articles detailing mixed methods research, there are relatively few published reports of its use in feminist study. This article draws on a study conducted in regional…

Mixed time integration methods for transient thermal analysis of structures, appendix 5

NASA Technical Reports Server (NTRS)

Liu, W. K.

1982-01-01

Mixed time integration methods for transient thermal analysis of structures are studied. An efficient solution procedure for predicting the thermal behavior of aerospace vehicle structures was developed. A 2D finite element computer program incorporating these methodologies is being implemented. The performance of these mixed time finite element algorithms can then be evaluated employing the proposed example problem.

A Mixed Methods Approach to Determining the Impact of a Geoscience Field Research Program upon Science Teachers' Knowledge, Beliefs, and Instructional Practices

ERIC Educational Resources Information Center

Luera, Gail; Murray, Kent

2016-01-01

A mixed methods research approach was used to investigate the impact of a geosciences research institute upon 62 science teachers' knowledge, beliefs, and teaching practices related to teaching the geosciences. Pre- and postinstitute quantitative and qualitative assessments revealed mixed results. Results of a quantitative measure found a…

Material nonlinear analysis via mixed-iterative finite element method

NASA Technical Reports Server (NTRS)

Sutjahjo, Edhi; Chamis, Christos C.

1992-01-01

The performance of elastic-plastic mixed-iterative analysis is examined through a set of convergence studies. Membrane and bending behaviors are tested using 4-node quadrilateral finite elements. The membrane result is excellent, which indicates the implementation of elastic-plastic mixed-iterative analysis is appropriate. On the other hand, further research to improve bending performance of the method seems to be warranted.

Precise Composition Tailoring of Mixed-Cation Hybrid Perovskites for Efficient Solar Cells by Mixture Design Methods.

PubMed

Li, Liang; Liu, Na; Xu, Ziqi; Chen, Qi; Wang, Xindong; Zhou, Huanping

2017-09-26

Mixed anion/cation perovskites absorber has been recently implemented to construct highly efficient single junction solar cells and tandem devices. However, considerable efforts are still required to map the composition-property relationship of the mixed perovskites absorber, which is essential to facilitate device design. Here we report the intensive exploration of mixed-cation perovskites in their compositional space with the assistance of a rational mixture design (MD) methods. Different from the previous linear search of the cation ratios, it is found that by employing the MD methods, the ternary composition can be tuned simultaneously following simplex lattice designs or simplex-centroid designs, which enable significantly reduced experiment/sampling size to unveil the composition-property relationship for mixed perovskite materials and to boost the resultant device efficiency. We illustrated the composition-property relationship of the mixed perovskites in multidimension and achieved an optimized power conversion efficiency of 20.99% in the corresponding device. Moreover, the method is demonstrated to be feasible to help adjust the bandgap through rational materials design, which can be further extended to other materials systems, not limited in polycrystalline perovskites films for photovoltaic applications only.

Higher and lowest order mixed finite element approximation of subsurface flow problems with solutions of low regularity

NASA Astrophysics Data System (ADS)

Bause, Markus

2008-02-01

In this work we study mixed finite element approximations of Richards' equation for simulating variably saturated subsurface flow and simultaneous reactive solute transport. Whereas higher order schemes have proved their ability to approximate reliably reactive solute transport (cf., e.g. [Bause M, Knabner P. Numerical simulation of contaminant biodegradation by higher order methods and adaptive time stepping. Comput Visual Sci 7;2004:61-78]), the Raviart- Thomas mixed finite element method ( RT0) with a first order accurate flux approximation is popular for computing the underlying water flow field (cf. [Bause M, Knabner P. Computation of variably saturated subsurface flow by adaptive mixed hybrid finite element methods. Adv Water Resour 27;2004:565-581, Farthing MW, Kees CE, Miller CT. Mixed finite element methods and higher order temporal approximations for variably saturated groundwater flow. Adv Water Resour 26;2003:373-394, Starke G. Least-squares mixed finite element solution of variably saturated subsurface flow problems. SIAM J Sci Comput 21;2000:1869-1885, Younes A, Mosé R, Ackerer P, Chavent G. A new formulation of the mixed finite element method for solving elliptic and parabolic PDE with triangular elements. J Comp Phys 149;1999:148-167, Woodward CS, Dawson CN. Analysis of expanded mixed finite element methods for a nonlinear parabolic equation modeling flow into variably saturated porous media. SIAM J Numer Anal 37;2000:701-724]). This combination might be non-optimal. Higher order techniques could increase the accuracy of the flow field calculation and thereby improve the prediction of the solute transport. Here, we analyse the application of the Brezzi- Douglas- Marini element ( BDM1) with a second order accurate flux approximation to elliptic, parabolic and degenerate problems whose solutions lack the regularity that is assumed in optimal order error analyses. For the flow field calculation a superiority of the BDM1 approach to the RT0 one is observed, which however is less significant for the accompanying solute transport.

Understanding the Experience of Stroke: A Mixed-Method Research Agenda

PubMed Central

Clarke, Philippa

2009-01-01

The use of both quantitative and qualitative strategies to examine a single research question has been a subject of considerable controversy and still remains a largely uncommon practice in the sociology of health and illness. Yet, when seeking to understand the meaning of a chronic disabling condition in later life from a social psychological perspective, a mixed-method approach is likely to provide the most comprehensive picture. This article provides an overview of the usefulness and appropriateness of a mixed-method approach to understanding the stroke experience. I comment on the current state of research on the experience of stroke, including epistemological and ontological orientations. Using real data examples, I address paradigmatic assumptions, methods of integration, as well as challenges and pitfalls in integrating methods. I conclude by considering future directions in this field of research. PMID:19386828

Incorporating Qualitative Evidence in Systematic Reviews: Strategies and Challenges

ERIC Educational Resources Information Center

Caracelli, Valerie J.; Cooksy, Leslie J.

2013-01-01

The quality of mixed methods systematic reviews relies on the quality of primary-level studies. The synthesis of qualitative evidence and the recent development of synthesizing mixed methods studies hold promise, but also pose challenges to evidence synthesis.

Virginia method for the design of dense-graded emulsion mixes.

DOT National Transportation Integrated Search

1982-01-01

An investigation into the Illinois method for the design of dense-graded emulsion base mixes had resulted in a report offering several modifications to that procedure. The Bituminous Research Advisory Committee then recommended that the Illinois meth...

Comparison of several asphalt design methods.

DOT National Transportation Integrated Search

1998-01-01

This laboratory study compared several methods of selecting the optimum asphalt content of surface mixes. Six surface mixes were tested using the 50-blow Marshall design, the 75-blow Marshall design, two brands of SHRP gyratory compactors, and the U....

The Use of Mixed Methods for Therapeutic Massage Research

PubMed Central

Porcino, Antony Joseph; Verhoef, Marja J.

2010-01-01

Mixed methods research is the integration of quantitative and qualitative components in a research project. Whether you are reading or designing a mixed methods research project, it is important to be familiar with both qualitative and quantitative research methods and the specific purposes for which they are brought together in a study: triangulation, complementarity, expansion, initiation, or development. In addition, decisions need to be made about the sequencing and the priority or importance of each qualitative and quantitative component relative to the other components, and the point or points at which the various qualitative and quantitative components will be integrated. Mixed methods research is increasingly being recognized for its ability to bring multiple points of view to a research project, taking advantage of the strengths of each of the quantitative and qualitative components to explain or resolve complex phenomena or results. This ability becomes critical when complex healing systems such as therapeutic massage are being studied. Complex healing systems may have multiple physiologic effects, often reflected in changes throughout the patient’s body. Additionally, the patient’s experience of the treatment may be an important outcome. PMID:21589698

Amperometric Enzyme Sensor to Check the Total Antioxidant Capacity of Several Mixed Berries. Comparison with Two Other Spectrophotometric and Fluorimetric Methods

PubMed Central

Tomassetti, Mauro; Serone, Maruschka; Angeloni, Riccardo; Campanella, Luigi; Mazzone, Elisa

2015-01-01

The aim of this research was to test the correctness of response of a superoxide dismutase amperometric biosensor used for the purpose of measuring and ranking the total antioxidant capacity of several systematically analysed mixed berries. Several methods are described in the literature for determining antioxidant capacity, each culminating in the construction of an antioxidant capacity scale and each using its own unit of measurement. It was therefore endeavoured to correlate and compare the results obtained using the present amperometric biosensor method with those resulting from two other different methods for determining the total antioxidant capacity selected from among those more frequently cited in the literature. The purpose was to establish a methodological approach consisting in the simultaneous application of different methods that it would be possible to use to obtain an accurate estimation of the total antioxidant capacity of different mixed berries and the food products containing them. Testing was therefore extended to also cover jams, yoghurts and juices containing mixed berries. PMID:25654720

Mixed-Method Nursing Research: "A Public and Its Problems?" A Commentary on French Nursing Research.

PubMed

Dupin, Cécile Marie; Debout, Christophe; Rothan-Tondeur, Monique

2014-02-01

Nursing in France is undergoing a transition. In 2009, the preregistration nursing education program was reformed in line with the European Bologna Process, bringing nursing education to the universities. In 2010, the French Programme Hospitalier de Recherche Infirmière, the first national French nursing research funding program, was launched by the French Health Ministry. Of the 149 French research proposals submitted by registered nurses in 2010 and 2011, 13 were mixed-method proposals. The registered nurse principal investigator argued for a complementary use of qualitative and quantitative methods. These trends highlight major issues regarding mixed-method and nursing research. We can reasonably assume that mixed-method research has a broad appeal for nurse scholars, particularly for the exploration of complex phenomena related to nursing. Moreover, the recent movement in the domain of nursing education and research experienced in France highlights the need for dedicated research education in the development of nursing research capacity. © The Author(s) 2014 Reprints and permissions:]br]sagepub.co.uk/journalsPermissions.nav.

Bridging the qualitative-quantitative divide: Experiences from conducting a mixed methods evaluation in the RUCAS programme.

PubMed

Makrakis, Vassilios; Kostoulas-Makrakis, Nelly

2016-02-01

Quantitative and qualitative approaches to planning and evaluation in education for sustainable development have often been treated by practitioners from a single research paradigm. This paper discusses the utility of mixed method evaluation designs which integrate qualitative and quantitative data through a sequential transformative process. Sequential mixed method data collection strategies involve collecting data in an iterative process whereby data collected in one phase contribute to data collected in the next. This is done through examples from a programme addressing the 'Reorientation of University Curricula to Address Sustainability (RUCAS): A European Commission Tempus-funded Programme'. It is argued that the two approaches are complementary and that there are significant gains from combining both. Using methods from both research paradigms does not, however, mean that the inherent differences among epistemologies and methodologies should be neglected. Based on this experience, it is recommended that using a sequential transformative mixed method evaluation can produce more robust results than could be accomplished using a single approach in programme planning and evaluation focussed on education for sustainable development. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mixing method and apparatus

DOEpatents

Green, Norman W.

1982-06-15

Method of mixing particulate materials comprising contacting a primary source and a secondary source thereof whereby resulting mixture ensues; preferably at least one of the two sources has enough motion to insure good mixing and the particulate materials may be heat treated if desired. Apparatus for such mixing comprising an inlet for a primary source, a reactor communicating therewith, a feeding means for supplying a secondary source to the reactor, and an inlet for the secondary source. Feeding means is preferably adapted to supply fluidized materials.

The value of automated gel column agglutination technology in the identification of true inherited D blood types in massively transfused patients.

PubMed

Summers, Thomas; Johnson, Viviana V; Stephan, John P; Johnson, Gloria J; Leonard, George

2009-08-01

Massive transfusion of D- trauma patients in the combat setting involves the use of D+ red blood cells (RBCs) or whole blood along with suboptimal pretransfusion test result documentation. This presents challenges to the transfusion service of tertiary care military hospitals who ultimately receive these casualties because initial D typing results may only reflect the transfused RBCs. After patients are stabilized, mixed-field reaction results on D typing indicate the patient's true inherited D phenotype. This case series illustrates the utility of automated gel column agglutination in detecting mixed-field reactions in these patients. The transfusion service test results, including the automated gel column agglutination D typing results, of four massively transfused D- patients transfused D+ RBCs is presented. To test the sensitivity of the automated gel column agglutination method in detecting mixed-field agglutination reactions, a comparative analysis of three automated technologies using predetermined mixtures of D+ and D- RBCs is also presented. The automated gel column agglutination method detected mixed-field agglutination in D typing in all four patients and in the three prepared control specimens. The automated microwell tube method identified one of the three prepared control specimens as indeterminate, which was subsequently manually confirmed as a mixed-field reaction. The automated solid-phase method was unable to detect any mixed fields. The automated gel column agglutination method provides a sensitive means for detecting mixed-field agglutination reactions in the determination of the true inherited D phenotype of combat casualties transfused massive amounts of D+ RBCs.

Electromagnetic stirring in a microbioreactor with non-conventional chamber morphology and implementation of multiplexed mixing.

PubMed

Tan, Christabel Kl; Davies, Matthew J; McCluskey, Daniel K; Munro, Ian R; Nweke, Mauryn C; Tracey, Mark C; Szita, Nicolas

2015-10-01

Microbioreactors have emerged as novel tools for early bioprocess development. Mixing lies at the heart of bioreactor operation (at all scales). The successful implementation of micro-stirring methods is thus central to the further advancement of microbioreactor technology. The aim of this study was to develop a micro-stirring method that aids robust microbioreactor operation and facilitates cost-effective parallelization. A microbioreactor was developed with a novel micro-stirring method involving the movement of a magnetic bead by sequenced activation of a ring of electromagnets. The micro-stirring method offers flexibility in chamber designs, and mixing is demonstrated in cylindrical, diamond and triangular shaped reactor chambers. Mixing was analyzed for different electromagnet on/off sequences; mixing times of 4.5 s, 2.9 s, and 2.5 s were achieved for cylindrical, diamond and triangular shaped chambers, respectively. Ease of micro-bubble free priming, a typical challenge of cylindrical shaped microbioreactor chambers, was obtained with a diamond-shaped chamber. Consistent mixing behavior was observed between the constituent reactors in a duplex system. A novel stirring method using electromagnetic actuation offering rapid mixing and easy integration with microbioreactors was characterized. The design flexibility gained enables fabrication of chambers suitable for microfluidic operation, and a duplex demonstrator highlights potential for cost-effective parallelization. Combined with a previously published cassette-like fabrication of microbioreactors, these advances will facilitate the development of robust and parallelized microbioreactors. © 2015 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

MIXING QUANTIFICATION BY VISUAL IMAGING ANALYSIS

EPA Science Inventory

This paper reports on development of a method for quantifying two measures of mixing, the scale and intensity of segregation, through flow visualization, video recording, and software analysis. This non-intrusive method analyzes a planar cross section of a flowing system from an ...

The promise of mixed-methods for advancing latino health research.

PubMed

Apesoa-Varano, Ester Carolina; Hinton, Ladson

2013-09-01

Mixed-methods research in the social sciences has been conducted for quite some time. More recently, mixed-methods have become popular in health research, with the National Institutes of Health leading the impetus to fund studies that implement such an approach. The public health issues facing us today are great and they range from policy and other macro-level issues, to systems level problems to individuals' health behaviors. For Latinos, who are projected to become the largest minority group bearing a great deal of the burden of social inequality in the U.S., it is important to understand the deeply-rooted nature of these health disparities in order to close the gap in health outcomes. Mixed-methodology thus holds promise for advancing research on Latino heath by tackling health disparities from a variety of standpoints and approaches. The aim of this manuscript is to provide two examples of mixed methods research, each of which addresses a health topic of considerable importance to older Latinos and their families. These two examples will illustrate a) the complementary use of qualitative and quantitative methods to advance health of older Latinos in an area that is important from a public health perspective, and b) the "translation" of findings from observational studies (informed by social science and medicine) to the development and testing of interventions.

Method of forming catalyst layer by single step infiltration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerdes, Kirk; Lee, Shiwoo; Dowd, Regis

Provided herein is a method for electrocatalyst infiltration of a porous substrate, of particular use for preparation of a cathode for a solid oxide fuel cell. The method generally comprises preparing an electrocatalyst infiltrate solution comprising an electrocatalyst, surfactant, chelating agent, and a solvent; pretreating a porous mixed ionic-electric conductive substrate; and applying the electrocatalyst infiltration solution to the porous mixed ionic-electric conductive substrate.

Decision Process to Identify Lessons for Transition to a Distributed (or Blended) Learning Instructional Format

DTIC Science & Technology

2009-09-01

instructional format. Using a mixed- method coding and analysis approach, the sample of POIs were categorized, coded, statistically analyzed, and a... Method SECURITY CLASSIFICATION OF 19. LIMITATION OF 20. NUMBER 21. RESPONSIBLE PERSON 16. REPORT Unclassified 17. ABSTRACT...transition to a distributed (or blended) learning format. Procedure: A mixed- methods approach, combining qualitative coding procedures with basic

Best Practices for Bullying Interventions Utilized in a Texas School District: A Mixed Method Study Examining How School Leaders Resolve Campus Bullying

ERIC Educational Resources Information Center

Tracy, Jennifer M.

2012-01-01

Purpose: The purpose of this mixed methods study was to investigate the best practices for bullying interventions. The participants for the quantitative data collection were counselors (n = 22) and principals (n = 20) located in elementary and junior high schools; 10 were selected to participate in the qualitative data collection. Method: The…

The Impact of Test Dimensionality, Common-Item Set Format, and Scale Linking Methods on Mixed-Format Test Equating

ERIC Educational Resources Information Center

Öztürk-Gübes, Nese; Kelecioglu, Hülya

2016-01-01

The purpose of this study was to examine the impact of dimensionality, common-item set format, and different scale linking methods on preserving equity property with mixed-format test equating. Item response theory (IRT) true-score equating (TSE) and IRT observed-score equating (OSE) methods were used under common-item nonequivalent groups design.…

Integrating Mixed Method Data in Psychological Research: Combining Q Methodology and Questionnaires in a Study Investigating Cultural and Psychological Influences on Adolescent Sexual Behavior

ERIC Educational Resources Information Center

Franz, Anke; Worrell, Marcia; Vögele, Claus

2013-01-01

In recent years, combining quantitative and qualitative research methods in the same study has become increasingly acceptable in both applied and academic psychological research. However, a difficulty for many mixed methods researchers is how to integrate findings consistently. The value of using a coherent framework throughout the research…

Using Interpretative Phenomenological Analysis in a Mixed Methods Research Design to Explore Music in the Lives of Mature Age Amateur Keyboard Players

ERIC Educational Resources Information Center

Taylor, Angela

2015-01-01

This article discusses the use of interpretative phenomenological analysis (IPA) in a mixed methods research design with reference to five recent publications about music in the lives of mature age amateur keyboard players. It explores the links between IPA and the data-gathering methods of "Rivers of Musical Experience",…

The adjusting factor method for weight-scaling truckloads of mixed hardwood sawlogs

Treesearch

Edward L. Adams

1976-01-01

A new method of weight-scaling truckloads of mixed hardwood sawlogs systematically adjusts for changes in the weight/volume ratio of logs coming into a sawmill. It uses a conversion factor based on the running average of weight/volume ratios of randomly selected sample loads. A test of the method indicated that over a period of time the weight-scaled volume should...

Diffusely reflecting paints including polytetrafluoroethylene and method of manufacture

NASA Technical Reports Server (NTRS)

Schutt, J. B.; Shai, M. C. (Inventor)

1985-01-01

The invention pertains to a high diffuse, reflective paint comprising an alcohol soluble binder, polytetrafluoroethylene (TFE) and an alcohol for coating a substrate and forming an optical reference with a superior Lambertian characteristic. A method for making the paint by first mixing the biner and alcohol, and thereafter by mixing in outgassed TFE is described. A wetting agent may be employed to aid the mixing process.

Preparation of uniform nanoparticles of ultra-high purity metal oxides, mixed metal oxides, metals, and metal alloys

DOEpatents

Woodfield, Brian F.; Liu, Shengfeng; Boerio-Goates, Juliana; Liu, Qingyuan; Smith, Stacey Janel

2012-07-03

In preferred embodiments, metal nanoparticles, mixed-metal (alloy) nanoparticles, metal oxide nanoparticles and mixed-metal oxide nanoparticles are provided. According to embodiments, the nanoparticles may possess narrow size distributions and high purities. In certain preferred embodiments, methods of preparing metal nanoparticles, mixed-metal nanoparticles, metal oxide nanoparticles and mixed-metal nanoparticles are provided. These methods may provide tight control of particle size, size distribution, and oxidation state. Other preferred embodiments relate to a precursor material that may be used to form nanoparticles. In addition, products prepared from such nanoparticles are disclosed.

Recovery of failed solid-state anaerobic digesters.

PubMed

Yang, Liangcheng; Ge, Xumeng; Li, Yebo

2016-08-01

This study examined the performance of three methods for recovering failed solid-state anaerobic digesters. The 9-L digesters, which were fed with corn stover, failed at a feedstock/inoculum (F/I) ratio of 10 with negligible methane yields. To recover the systems, inoculum was added to bring the F/I ratio to 4. Inoculum was either added to the top of a failed digester, injected into it, or well-mixed with the existing feedstock. Digesters using top-addition and injection methods quickly resumed and achieved peak yields in 10days, while digesters using well-mixed method recovered slowly but showed 50% higher peak yields. Overall, these methods recovered 30-40% methane from failed digesters. The well-mixed method showed the highest methane yield, followed by the injection and top-addition methods. Recovered digesters outperformed digesters had a constant F/I ratio of 4. Slow mass transfer and slow growth of microbes were believed to be the major limiting factors for recovery. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mixed methods research - the best of both worlds?

PubMed

van Griensven, Hubert; Moore, Ann P; Hall, Valerie

2014-10-01

There has been a bias towards quantitative research approaches within manual therapy, which may have resulted in a narrow understanding of manual therapy practice. The aim of this Masterclass is to make a contribution to the expansion of methodologies used in manual therapy enquiry by discussing mixed methods research (MMR), a methodology which utilises both qualitative and quantitative methods within a single study in order to provide more comprehensive insights. To review rationales for MMR, as well as some of the common design options and potential difficulties. The paper also discusses theoretical frameworks that have been used to underpin qualitative and quantitative research, and ongoing debates about the possibility of combining them. Complexities associated with health and manual therapy cannot always be investigated satisfactorily by using a single research method. Some issues require a more comprehensive understanding, which may be provided by combining the strengths of quantitative and qualitative methods in a mixed methods study. Copyright © 2014 Elsevier Ltd. All rights reserved.

Method for low temperature preparation of a noble metal alloy

DOEpatents

Even, Jr., William R.

2002-01-01

A method for producing fine, essentially contamination free, noble metal alloys is disclosed. The alloys comprise particles in a size range of 5 to 500 nm. The method comprises 1. A method for preparing a noble metal alloy at low temperature, the method comprising the steps of forming solution of organometallic compounds by dissolving the compounds into a quantity of a compatible solvent medium capable of solvating the organometallic, mixing a portion of each solution to provide a desired molarity ratio of ions in the mixed solution, adding a support material, rapidly quenching droplets of the mixed solution to initiate a solute-solvent phase separation as the solvent freezes, removing said liquid cryogen, collecting and freezing drying the frozen droplets to produce a dry powder, and finally reducing the powder to a metal by flowing dry hydrogen over the powder while warming the powder to a temperature of about 150.degree. C.

Use of recycled chunk rubber asphalt concrete (CRAC) on low volume roads and use of recycled crumb rubber modifier in asphalt pavements. Final report, June 1993-June 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hossain, M.; Funk, L.P.; Sadeq, M.A.

1995-06-01

The major objective of this project was to formulate a Chunk Rubber Asphalt Concrete (CRAC) mix for use on low volume roads. CRAC is a rubber modified asphalt concrete product produced by the `dry process` where rubber chunks of 1/2 inch size are used as aggregate in a cold mix with a type C fly ash. The second objective of this project was to develop guidelines concerning the use of rubber modified asphalt concrete hot mix to include: (1) Design methods for use of asphalt-rubber mix for new construction and overlay, (2) Mix design method for asphalt-rubber, and (3) Testmore » method for determining the amount of rubber in an asphalt-rubber concrete for quality control purposes.« less

Applying Mixed Methods Research at the Synthesis Level: An Overview

ERIC Educational Resources Information Center

Heyvaert, Mieke; Maes, Bea; Onghena, Patrick

2011-01-01

Historically, qualitative and quantitative approaches have been applied relatively separately in synthesizing qualitative and quantitative evidence, respectively, in several research domains. However, mixed methods approaches are becoming increasingly popular nowadays, and practices of combining qualitative and quantitative research components at…

Plastometry for the Self-Compacting Concrete Mixes

NASA Astrophysics Data System (ADS)

Lapsa, V. Ā.; Krasnikovs, A.; Lusis, V.; Lukasenoks, A.

2015-11-01

Operative determination of consistence of self-compacting concrete mixes at plant or in construction conditions is an important problem in building practice. The Abram's cone, the Vebe's device, the U-box siphon, L-box or funnel tests are used in solving this problem. However, these field methods are targeted at determination of some indirect parameters of such very complicated paste-like material like concrete mix. They are not physical characteristics suitable for the rheological calculations of the coherence between the stress and strains, flow characteristics and the reaction of the concrete mix in different technological processes. A conical plastometer having higher precision and less sensitive to the inaccuracy of the tests in construction condition has been elaborated at the Concrete Mechanics Laboratory of RTU. In addition, a new method was elaborated for the calculation of plasticity limit τ0 taking into account the buoyancy force of the liquid or non-liquid concrete mix. In the present investigation rheological test of the concrete mix by use the plastometer and the method mentioned earlier was conducted for different self-compacting and not self-compacting concrete mixes.

An apparatus for sequentially combining microvolumes of reagents by infrasonic mixing.

PubMed

Camien, M N; Warner, R C

1984-05-01

A method employing high-speed infrasonic mixing for obtaining timed samples for following the progress of a moderately rapid chemical reaction is described. Drops of 10 to 50 microliter each of two reagents are mixed to initiate the reaction, followed, after a measured time interval, by mixing with a drop of a third reagent to quench the reaction. The method was developed for measuring the rate of denaturation of covalently closed, circular DNA in NaOH at several temperatures. For this purpose the timed samples were analyzed by analytical ultracentrifugation. The apparatus was tested by determination of the rate of hydrolysis of 2,4-dinitrophenyl acetate in an alkaline buffer. The important characteristics of the method are (i) it requires very small volumes of sample and reagents; (ii) the components of the reaction mixture are pre-equilibrated and mixed with no transfer outside the prescribed constant temperature environment; (iii) the mixing is very rapid; and (iv) satisfactorily precise measurements of relatively short time intervals (approximately 2 sec minimum) between sequential mixings of the components are readily obtainable.

Development of an Empirical Methods for Predicting Jet Mixing Noise of Cold Flow Rectangular Jets

NASA Technical Reports Server (NTRS)

Russell, James W.

1999-01-01

This report presents an empirical method for predicting the jet mixing noise levels of cold flow rectangular jets. The report presents a detailed analysis of the methodology used in development of the prediction method. The empirical correlations used are based on narrow band acoustic data for cold flow rectangular model nozzle tests conducted in the NASA Langley Jet Noise Laboratory. There were 20 separate nozzle test operating conditions. For each operating condition 60 Hz bandwidth microphone measurements were made over a frequency range from 0 to 60,000 Hz. Measurements were performed at 16 polar directivity angles ranging from 45 degrees to 157.5 degrees. At each polar directivity angle, measurements were made at 9 azimuth directivity angles. The report shows the methods employed to remove screech tones and shock noise from the data in order to obtain the jet mixing noise component. The jet mixing noise was defined in terms of one third octave band spectral content, polar and azimuth directivity, and overall power level. Empirical correlations were performed over the range of test conditions to define each of these jet mixing noise parameters as a function of aspect ratio, jet velocity, and polar and azimuth directivity angles. The report presents the method for predicting the overall power level, the average polar directivity, the azimuth directivity and the location and shape of the spectra for jet mixing noise of cold flow rectangular jets.

Predicting Displaceable Water Sites Using Mixed-Solvent Molecular Dynamics.

PubMed

Graham, Sarah E; Smith, Richard D; Carlson, Heather A

2018-02-26

Water molecules are an important factor in protein-ligand binding. Upon binding of a ligand with a protein's surface, waters can either be displaced by the ligand or may be conserved and possibly bridge interactions between the protein and ligand. Depending on the specific interactions made by the ligand, displacing waters can yield a gain in binding affinity. The extent to which binding affinity may increase is difficult to predict, as the favorable displacement of a water molecule is dependent on the site-specific interactions made by the water and the potential ligand. Several methods have been developed to predict the location of water sites on a protein's surface, but the majority of methods are not able to take into account both protein dynamics and the interactions made by specific functional groups. Mixed-solvent molecular dynamics (MixMD) is a cosolvent simulation technique that explicitly accounts for the interaction of both water and small molecule probes with a protein's surface, allowing for their direct competition. This method has previously been shown to identify both active and allosteric sites on a protein's surface. Using a test set of eight systems, we have developed a method using MixMD to identify conserved and displaceable water sites. Conserved sites can be determined by an occupancy-based metric to identify sites which are consistently occupied by water even in the presence of probe molecules. Conversely, displaceable water sites can be found by considering the sites which preferentially bind probe molecules. Furthermore, the inclusion of six probe types allows the MixMD method to predict which functional groups are capable of displacing which water sites. The MixMD method consistently identifies sites which are likely to be nondisplaceable and predicts the favorable displacement of water sites that are known to be displaced upon ligand binding.

Quantification of polyhydroxyalkanoates in mixed and pure cultures biomass by Fourier transform infrared spectroscopy: comparison of different approaches.

PubMed

Isak, I; Patel, M; Riddell, M; West, M; Bowers, T; Wijeyekoon, S; Lloyd, J

2016-08-01

Fourier transform infrared (FTIR) spectroscopy was used in this study for the rapid quantification of polyhydroxyalkanoates (PHA) in mixed and pure culture bacterial biomass. Three different statistical analysis methods (regression, partial least squares (PLS) and nonlinear) were applied to the FTIR data and the results were plotted against the PHA values measured with the reference gas chromatography technique. All methods predicted PHA content in mixed culture biomass with comparable efficiency, indicated by similar residuals values. The PHA in these cultures ranged from low to medium concentration (0-44 wt% of dried biomass content). However, for the analysis of the combined mixed and pure culture biomass with PHA concentration ranging from low to high (0-93% of dried biomass content), the PLS method was most efficient. This paper reports, for the first time, the use of a single calibration model constructed with a combination of mixed and pure cultures covering a wide PHA range, for predicting PHA content in biomass. Currently no one universal method exists for processing FTIR data for polyhydroxyalkanoates (PHA) quantification. This study compares three different methods of analysing FTIR data for quantification of PHAs in biomass. A new data-processing approach was proposed and the results were compared against existing literature methods. Most publications report PHA quantification of medium range in pure culture. However, in our study we encompassed both mixed and pure culture biomass containing a broader range of PHA in the calibration curve. The resulting prediction model is useful for rapid quantification of a wider range of PHA content in biomass. © 2016 The Society for Applied Microbiology.

Methods for analysis of cracks in three-dimensional solids

NASA Technical Reports Server (NTRS)

Raju, I. S.; Newman, J. C., Jr.

1984-01-01

Analytical and numerical methods evaluating the stress-intensity factors for three-dimensional cracks in solids are presented, with reference to fatigue failure in aerospace structures. The exact solutions for embedded elliptical and circular cracks in infinite solids, and the approximate methods, including the finite-element, the boundary-integral equation, the line-spring models, and the mixed methods are discussed. Among the mixed methods, the superposition of analytical and finite element methods, the stress-difference, the discretization-error, the alternating, and the finite element-alternating methods are reviewed. Comparison of the stress-intensity factor solutions for some three-dimensional crack configurations showed good agreement. Thus, the choice of a particular method in evaluating the stress-intensity factor is limited only to the availability of resources and computer programs.

Quantifying uncertainty in stable isotope mixing models

DOE PAGES

Davis, Paul; Syme, James; Heikoop, Jeffrey; ...

2015-05-19

Mixing models are powerful tools for identifying biogeochemical sources and determining mixing fractions in a sample. However, identification of actual source contributors is often not simple, and source compositions typically vary or even overlap, significantly increasing model uncertainty in calculated mixing fractions. This study compares three probabilistic methods, SIAR [ Parnell et al., 2010] a pure Monte Carlo technique (PMC), and Stable Isotope Reference Source (SIRS) mixing model, a new technique that estimates mixing in systems with more than three sources and/or uncertain source compositions. In this paper, we use nitrate stable isotope examples (δ 15N and δ 18O) butmore » all methods tested are applicable to other tracers. In Phase I of a three-phase blind test, we compared methods for a set of six-source nitrate problems. PMC was unable to find solutions for two of the target water samples. The Bayesian method, SIAR, experienced anchoring problems, and SIRS calculated mixing fractions that most closely approximated the known mixing fractions. For that reason, SIRS was the only approach used in the next phase of testing. In Phase II, the problem was broadened where any subset of the six sources could be a possible solution to the mixing problem. Results showed a high rate of Type I errors where solutions included sources that were not contributing to the sample. In Phase III some sources were eliminated based on assumed site knowledge and assumed nitrate concentrations, substantially reduced mixing fraction uncertainties and lowered the Type I error rate. These results demonstrate that valuable insights into stable isotope mixing problems result from probabilistic mixing model approaches like SIRS. The results also emphasize the importance of identifying a minimal set of potential sources and quantifying uncertainties in source isotopic composition as well as demonstrating the value of additional information in reducing the uncertainty in calculated mixing fractions.« less

Shielding methods of quasilaminar jets outflowing from plasma torch with interelectrode insert

NASA Astrophysics Data System (ADS)

Solonenko, O. P.; Smirnov, A. V.

2017-05-01

Investigations of two methods of protection against mixing of surrounding air atmosphere with the free lengthy jets outflowing at low Reynolds numbers from plasma torches with interelectrode insertion (IEI) were carried out. The offered methods allow to significantly reduce the mixing of oxygen with plasma jets that gives a possibility of synthesis, treatment and spraying of powder materials, as well as melting of coatings critical to oxidation.

On the optimization of a mixed speaker array in an enclosed space using the virtual-speaker weighting method

NASA Astrophysics Data System (ADS)

Peng, Bo; Zheng, Sifa; Liao, Xiangning; Lian, Xiaomin

2018-03-01

In order to achieve sound field reproduction in a wide frequency band, multiple-type speakers are used. The reproduction accuracy is not only affected by the signals sent to the speakers, but also depends on the position and the number of each type of speaker. The method of optimizing a mixed speaker array is investigated in this paper. A virtual-speaker weighting method is proposed to optimize both the position and the number of each type of speaker. In this method, a virtual-speaker model is proposed to quantify the increment of controllability of the speaker array when the speaker number increases. While optimizing a mixed speaker array, the gain of the virtual-speaker transfer function is used to determine the priority orders of the candidate speaker positions, which optimizes the position of each type of speaker. Then the relative gain of the virtual-speaker transfer function is used to determine whether the speakers are redundant, which optimizes the number of each type of speaker. Finally the virtual-speaker weighting method is verified by reproduction experiments of the interior sound field in a passenger car. The results validate that the optimum mixed speaker array can be obtained using the proposed method.

Novel method for immunofluorescence staining of mammalian eggs using non-contact alternating-current electric-field mixing of microdroplets

PubMed Central

Hiromitsu, Shirasawa; Jin, Kumagai; Emiko, Sato; Katsuya, Kabashima; Yukiyo, Kumazawa; Wataru, Sato; Hiroshi, Miura; Ryuta, Nakamura; Hiroshi, Nanjo; Yoshihiro, Minamiya; Yoichi, Akagami; Yukihiro, Terada

2015-01-01

Recently, a new technique was developed for non-catalytically mixing microdroplets. In this method, an alternating-current (AC) electric field is used to promote the antigen–antibody reaction within the microdroplet. Previously, this technique has only been applied to histological examinations of flat structures, such as surgical specimens. In this study, we applied this technique for the first time to immunofluorescence staining of three-dimensional structures, specifically, mammalian eggs. We diluted an antibody against microtubules from 1:1,000 to 1:16,000, and compared the chromatic degree and extent of fading across dilutions. In addition, we varied the frequency of AC electric-field mixing from 5 Hz to 46 Hz and evaluated the effect on microtubule staining. Microtubules were more strongly stained after AC electric-field mixing for only 5 minutes, even when the concentration of primary antibody was 10 times lower than in conventional methods. AC electric-field mixing also alleviated microtubule fading. At all frequencies tested, AC electric-field mixing resulted in stronger microtubule staining than in controls. There was no clear difference in a microtubule staining between frequencies. These results suggest that the novel method could reduce antibody consumption and shorten immunofluorescence staining time. PMID:26477850

Doing Interdisciplinary Mixed Methods Health Care Research: Working the Boundaries, Tensions, and Synergistic Potential of Team-Based Research.

PubMed

Hesse-Biber, Sharlene

2016-04-01

Current trends in health care research point to a shift from disciplinary models to interdisciplinary team-based mixed methods inquiry designs. This keynote address discusses the problems and prospects of creating vibrant mixed methods health care interdisciplinary research teams that can harness their potential synergy that holds the promise of addressing complex health care issues. We examine the range of factors and issues these types of research teams need to consider to facilitate efficient interdisciplinary mixed methods team-based research. It is argued that concepts such as disciplinary comfort zones, a lack of attention to team dynamics, and low levels of reflexivity among interdisciplinary team members can inhibit the effectiveness of a research team. This keynote suggests a set of effective strategies to address the issues that emanate from the new field of research inquiry known as team science as well as lessons learned from tapping into research on organizational dynamics. © The Author(s) 2016.

Mixed methods for implementation research: application to evidence-based practice implementation and staff turnover in community-based organizations providing child welfare services.

PubMed

Aarons, Gregory A; Fettes, Danielle L; Sommerfeld, David H; Palinkas, Lawrence A

2012-02-01

Many public sector service systems and provider organizations are in some phase of learning about or implementing evidence-based interventions. Child welfare service systems represent a context where implementation spans system, management, and organizational concerns. Research utilizing mixed methods that combine qualitative and quantitative design, data collection, and analytic approaches are particularly well suited to understanding both the process and outcomes of dissemination and implementation efforts in child welfare systems. This article describes the process of using mixed methods in implementation research and provides an applied example of an examination of factors impacting staff retention during an evidence-based intervention implementation in a statewide child welfare system. The authors integrate qualitative data with previously published quantitative analyses of job autonomy and staff turnover during this statewide implementation project in order to illustrate the utility of mixed method approaches in providing a more comprehensive understanding of opportunities and challenges in implementation research.

Subpixel Mapping of Hyperspectral Image Based on Linear Subpixel Feature Detection and Object Optimization

NASA Astrophysics Data System (ADS)

Liu, Zhaoxin; Zhao, Liaoying; Li, Xiaorun; Chen, Shuhan

2018-04-01

Owing to the limitation of spatial resolution of the imaging sensor and the variability of ground surfaces, mixed pixels are widesperead in hyperspectral imagery. The traditional subpixel mapping algorithms treat all mixed pixels as boundary-mixed pixels while ignoring the existence of linear subpixels. To solve this question, this paper proposed a new subpixel mapping method based on linear subpixel feature detection and object optimization. Firstly, the fraction value of each class is obtained by spectral unmixing. Secondly, the linear subpixel features are pre-determined based on the hyperspectral characteristics and the linear subpixel feature; the remaining mixed pixels are detected based on maximum linearization index analysis. The classes of linear subpixels are determined by using template matching method. Finally, the whole subpixel mapping results are iteratively optimized by binary particle swarm optimization algorithm. The performance of the proposed subpixel mapping method is evaluated via experiments based on simulated and real hyperspectral data sets. The experimental results demonstrate that the proposed method can improve the accuracy of subpixel mapping.

Mathematical model and metaheuristics for simultaneous balancing and sequencing of a robotic mixed-model assembly line

NASA Astrophysics Data System (ADS)

Li, Zixiang; Janardhanan, Mukund Nilakantan; Tang, Qiuhua; Nielsen, Peter

2018-05-01

This article presents the first method to simultaneously balance and sequence robotic mixed-model assembly lines (RMALB/S), which involves three sub-problems: task assignment, model sequencing and robot allocation. A new mixed-integer programming model is developed to minimize makespan and, using CPLEX solver, small-size problems are solved for optimality. Two metaheuristics, the restarted simulated annealing algorithm and co-evolutionary algorithm, are developed and improved to address this NP-hard problem. The restarted simulated annealing method replaces the current temperature with a new temperature to restart the search process. The co-evolutionary method uses a restart mechanism to generate a new population by modifying several vectors simultaneously. The proposed algorithms are tested on a set of benchmark problems and compared with five other high-performing metaheuristics. The proposed algorithms outperform their original editions and the benchmarked methods. The proposed algorithms are able to solve the balancing and sequencing problem of a robotic mixed-model assembly line effectively and efficiently.

Mixed Methods for Implementation Research: Application to Evidence-Based Practice Implementation and Staff Turnover in Community Based Organizations Providing Child Welfare Services

PubMed Central

Aarons, Gregory A.; Fettes, Danielle L.; Sommerfeld, David H.; Palinkas, Lawrence

2013-01-01

Many public sector services systems and provider organizations are in some phase of learning about or implementing evidence-based interventions. Child welfare service systems represent a context where implementation spans system, management, and organizational concerns. Research utilizing mixed methods that combine qualitative and quantitative design, data collection, and analytic approaches are particularly well-suited to understanding both the process and outcomes of dissemination and implementation efforts in child welfare systems. This paper describes the process of using mixed methods in implementation research and provides an applied example of an examination of factors impacting staff retention during an evidence-based intervention implementation in a statewide child welfare system. We integrate qualitative data with previously published quantitative analyses of job autonomy and staff turnover during this statewide implementation project in order to illustrate the utility of mixed method approaches in providing a more comprehensive understanding of opportunities and challenges in implementation research. PMID:22146861

A Mixed Prioritization Operators Strategy Using A Single Measurement Criterion For AHP Application Development

NASA Astrophysics Data System (ADS)

Yuen, Kevin Kam Fung

2009-10-01

The most appropriate prioritization method is still one of the unsettled issues of the Analytic Hierarchy Process, although many studies have been made and applied. Interestingly, many AHP applications apply only Saaty's Eigenvector method as many studies have found that this method may produce rank reversals and have proposed various prioritization methods as alternatives. Some methods have been proved to be better than the Eigenvector method. However, these methods seem not to attract the attention of researchers. In this paper, eight important prioritization methods are reviewed. A Mixed Prioritization Operators Strategy (MPOS) is developed to select a vector which is prioritized by the most appropriate prioritization operator. To verify this new method, a case study of high school selection is revised using the proposed method. The contribution is that MPOS is useful for solving prioritization problems in the AHP.

Clustering of Variables for Mixed Data

NASA Astrophysics Data System (ADS)

Saracco, J.; Chavent, M.

2016-05-01

This chapter presents clustering of variables which aim is to lump together strongly related variables. The proposed approach works on a mixed data set, i.e. on a data set which contains numerical variables and categorical variables. Two algorithms of clustering of variables are described: a hierarchical clustering and a k-means type clustering. A brief description of PCAmix method (that is a principal component analysis for mixed data) is provided, since the calculus of the synthetic variables summarizing the obtained clusters of variables is based on this multivariate method. Finally, the R packages ClustOfVar and PCAmixdata are illustrated on real mixed data. The PCAmix and ClustOfVar approaches are first used for dimension reduction (step 1) before applying in step 2 a standard clustering method to obtain groups of individuals.

Microreactor and method for preparing a radiolabeled complex or a biomolecule conjugate

DOEpatents

Reichert, David E; Kenis, Paul J. A.; Wheeler, Tobias D; Desai, Amit V; Zeng, Dexing; Onal, Birce C

2015-03-17

A microreactor for preparing a radiolabeled complex or a biomolecule conjugate comprises a microchannel for fluid flow, where the microchannel comprises a mixing portion comprising one or more passive mixing elements, and a reservoir for incubating a mixed fluid. The reservoir is in fluid communication with the microchannel and is disposed downstream of the mixing portion. A method of preparing a radiolabeled complex includes flowing a radiometal solution comprising a metallic radionuclide through a downstream mixing portion of a microchannel, where the downstream mixing portion includes one or more passive mixing elements, and flowing a ligand solution comprising a bifunctional chelator through the downstream mixing portion. The ligand solution and the radiometal solution are passively mixed while in the downstream mixing portion to initiate a chelation reaction between the metallic radionuclide and the bifunctional chelator. The chelation reaction is completed to form a radiolabeled complex.

Testing the reliability and efficiency of the pilot Mixed Methods Appraisal Tool (MMAT) for systematic mixed studies review.

PubMed

Pace, Romina; Pluye, Pierre; Bartlett, Gillian; Macaulay, Ann C; Salsberg, Jon; Jagosh, Justin; Seller, Robbyn

2012-01-01

Systematic literature reviews identify, select, appraise, and synthesize relevant literature on a particular topic. Typically, these reviews examine primary studies based on similar methods, e.g., experimental trials. In contrast, interest in a new form of review, known as mixed studies review (MSR), which includes qualitative, quantitative, and mixed methods studies, is growing. In MSRs, reviewers appraise studies that use different methods allowing them to obtain in-depth answers to complex research questions. However, appraising the quality of studies with different methods remains challenging. To facilitate systematic MSRs, a pilot Mixed Methods Appraisal Tool (MMAT) has been developed at McGill University (a checklist and a tutorial), which can be used to concurrently appraise the methodological quality of qualitative, quantitative, and mixed methods studies. The purpose of the present study is to test the reliability and efficiency of a pilot version of the MMAT. The Center for Participatory Research at McGill conducted a systematic MSR on the benefits of Participatory Research (PR). Thirty-two PR evaluation studies were appraised by two independent reviewers using the pilot MMAT. Among these, 11 (34%) involved nurses as researchers or research partners. Appraisal time was measured to assess efficiency. Inter-rater reliability was assessed by calculating a kappa statistic based on dichotomized responses for each criterion. An appraisal score was determined for each study, which allowed the calculation of an overall intra-class correlation. On average, it took 14 min to appraise a study (excluding the initial reading of articles). Agreement between reviewers was moderate to perfect with regards to MMAT criteria, and substantial with respect to the overall quality score of appraised studies. The MMAT is unique, thus the reliability of the pilot MMAT is promising, and encourages further development. Copyright © 2011 Elsevier Ltd. All rights reserved.

An equivalent domain integral method in the two-dimensional analysis of mixed mode crack problems

NASA Technical Reports Server (NTRS)

Raju, I. S.; Shivakumar, K. N.

1990-01-01

An equivalent domain integral (EDI) method for calculating J-integrals for two-dimensional cracked elastic bodies is presented. The details of the method and its implementation are presented for isoparametric elements. The EDI method gave accurate values of the J-integrals for two mode I and two mixed mode problems. Numerical studies showed that domains consisting of one layer of elements are sufficient to obtain accurate J-integral values. Two procedures for separating the individual modes from the domain integrals are presented.

Workplace-related generational characteristics of nurses: A mixed-method systematic review.

PubMed

Stevanin, Simone; Palese, Alvisa; Bressan, Valentina; Vehviläinen-Julkunen, Katri; Kvist, Tarja

2018-06-01

The aim of this study was to describe and summarize workplace characteristics of three nursing generations: Baby Boomers, Generations X and Y. Generational differences affect occupational well-being, nurses' performance, patient outcomes and safety; therefore, nurse managers, administrators and educators are interested increasingly in making evidence-based decisions about the multigenerational nursing workforce. Mixed-method systematic review. Medline, CINAHL, PsycINFO and Scopus (January 1991-January 2017). (1) The Joanna Briggs Institute's method for conducting mixed-method systematic reviews; (2) the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and (3) the Enhancing Transparency in Reporting the Synthesis of Qualitative Research guidelines. The studies' methodological quality was assessed with the Mixed-Methods Appraisal Tool. Quantitative and mixed-method studies were transformed into qualitative methods using a convergent qualitative synthesis and qualitative findings were combined with a narrative synthesis. Thirty-three studies were included with three main themes and 11 subthemes: (1) Job attitudes (work engagement; turnover intentions, reasons for leaving; reasons, incentives/disincentives to continue nursing); (2) Emotion-related job aspects (stress/resilience; well-being/job satisfaction; affective commitment; unit climate; work ethic) and (3) Practice and leadership-related aspects (autonomy; perceived competence; leadership relationships and perceptions). Baby Boomers reported lower levels of stress and burnout than did Generations X and Y, different work engagement, factors affecting workplace well-being and retention and greater intention to leave compared with Generation Y, which was less resilient, but more cohesive. Although several studies reported methodological limitations and conflicting findings, generational differences in nurses' job attitudes, emotional, practice and leadership factors should be considered to enhance workplace quality. © 2018 John Wiley & Sons Ltd.

Model reduction method using variable-separation for stochastic saddle point problems

NASA Astrophysics Data System (ADS)

Jiang, Lijian; Li, Qiuqi

2018-02-01

In this paper, we consider a variable-separation (VS) method to solve the stochastic saddle point (SSP) problems. The VS method is applied to obtain the solution in tensor product structure for stochastic partial differential equations (SPDEs) in a mixed formulation. The aim of such a technique is to construct a reduced basis approximation of the solution of the SSP problems. The VS method attempts to get a low rank separated representation of the solution for SSP in a systematic enrichment manner. No iteration is performed at each enrichment step. In order to satisfy the inf-sup condition in the mixed formulation, we enrich the separated terms for the primal system variable at each enrichment step. For the SSP problems by regularization or penalty, we propose a more efficient variable-separation (VS) method, i.e., the variable-separation by penalty method. This can avoid further enrichment of the separated terms in the original mixed formulation. The computation of the variable-separation method decomposes into offline phase and online phase. Sparse low rank tensor approximation method is used to significantly improve the online computation efficiency when the number of separated terms is large. For the applications of SSP problems, we present three numerical examples to illustrate the performance of the proposed methods.

A comparison of moment-based methods of estimation for the log Pearson type 3 distribution

NASA Astrophysics Data System (ADS)

Koutrouvelis, I. A.; Canavos, G. C.

2000-06-01

The log Pearson type 3 distribution is a very important model in statistical hydrology, especially for modeling annual flood series. In this paper we compare the various methods based on moments for estimating quantiles of this distribution. Besides the methods of direct and mixed moments which were found most successful in previous studies and the well-known indirect method of moments, we develop generalized direct moments and generalized mixed moments methods and a new method of adaptive mixed moments. The last method chooses the orders of two moments for the original observations by utilizing information contained in the sample itself. The results of Monte Carlo experiments demonstrated the superiority of this method in estimating flood events of high return periods when a large sample is available and in estimating flood events of low return periods regardless of the sample size. In addition, a comparison of simulation and asymptotic results shows that the adaptive method may be used for the construction of meaningful confidence intervals for design events based on the asymptotic theory even with small samples. The simulation results also point to the specific members of the class of generalized moments estimates which maintain small values for bias and/or mean square error.

27 CFR 19.456 - Adding denaturants.

Code of Federal Regulations, 2010 CFR

2010-04-01

... methods of mixing denaturants and spirits if he deems such denaturation will not hinder effective... Denaturation § 19.456 Adding denaturants. Denaturants and spirits shall be mixed in packages, tanks, or bulk... proprietor shall submit a flow diagram of the intended process or method of adding denaturants. (Sec. 201...

Comparison of fundamental and simulative test methods for evaluating permanent deformation of hot mix asphalt

DOT National Transportation Integrated Search

2002-10-01

Rutting has long been a problem in hot mix asphalt (HMA) pavement. Through the years, researchers have used different kinds of fundamental and simulative test methods to estimate the rutting performance of HMA. It has been recognized that most fundam...

Credible Phenomenological Research: A Mixed-Methods Study

ERIC Educational Resources Information Center

Flynn, Stephen V.; Korcuska, James S.

2018-01-01

The authors conducted a 3-phase investigation into the credible standards for phenomenological research practices identified in the literature and endorsed by a sample of counselor education qualitative research experts. Utilizing a mixed-methods approach, the findings offer evidence that professional counseling has a distinctive format in which…

Mixed Methods Sampling: A Typology with Examples

ERIC Educational Resources Information Center

Teddlie, Charles; Yu, Fen

2007-01-01

This article presents a discussion of mixed methods (MM) sampling techniques. MM sampling involves combining well-established qualitative and quantitative techniques in creative ways to answer research questions posed by MM research designs. Several issues germane to MM sampling are presented including the differences between probability and…

Generational Learning Style Preferences Based on Computer-Based Healthcare Training

ERIC Educational Resources Information Center

Knight, Michaelle H.

2016-01-01

Purpose. The purpose of this mixed-method study was to determine the degree of perceived differences for auditory, visual and kinesthetic learning styles of Traditionalist, Baby Boomers, Generation X and Millennial generational healthcare workers participating in technology-assisted healthcare training. Methodology. This mixed-method research…

Assessing Affective Constructs in Reading: A Mixed Methods Study

ERIC Educational Resources Information Center

Conradi, Kristin

2011-01-01

Research investigating affective dimensions in reading has long been plagued by vaguely defined constructs and, consequently, by an array of potentially problematic instruments designed to measure them. This mixed-methods study investigated the relationship among three popular group-administered instruments intended to tap affective constructs in…

The Complexities of Teachers' Commitment to Environmental Education: A Mixed Methods Approach

ERIC Educational Resources Information Center

Sosu, Edward M.; McWilliam, Angus; Gray, Donald S.

2008-01-01

This article argues that a mixed methods approach is useful in understanding the complexity that underlies teachers' commitment to environmental education. Using sequential and concurrent procedures, the authors demonstrate how different methodological approaches highlighted different aspects of teacher commitment. The quantitative survey examined…

Differences in Student Reasoning about Belief-Relevant Arguments: A Mixed Methods Study

ERIC Educational Resources Information Center

McCrudden, Matthew T.; Barnes, Ashleigh

2016-01-01

This mixed methods study investigated high school students' evaluations of scientific arguments. Myside bias occurs when individuals evaluate belief-consistent information more favorably than belief-inconsistent information. In the quantitative phase, participants (n = 72 males) rated belief-consistent arguments more favorably than…

Triangulation 2.0

ERIC Educational Resources Information Center

Denzin, Norman K.

2012-01-01

The author's thesis is simple and direct. Those in the mixed methods qualitative inquiry community need a new story line, one that does not confuse pragmatism for triangulation, and triangulation for mixed methods research (MMR). A different third way is required, one that inspires generative politics and dialogic democracy and helps shape…

The "Movement" of Mixed Methods Research and the Role of Educators

ERIC Educational Resources Information Center

Creswell, John W.; Garrett, Amanda L.

2008-01-01

The landscape of research is continually evolving, enabling researchers to study increasingly complex phenomena. Educational researchers have propelled much of this forward progress and have developed novel methodologies to provide increasingly sound and complete evidence. Mixed methods research has emerged alongside quantitative and qualitative…

Investigating Learning with an Interactive Tutorial: A Mixed-Methods Strategy

ERIC Educational Resources Information Center

de Villiers, M. R.; Becker, Daphne

2017-01-01

From the perspective of parallel mixed-methods research, this paper describes interactivity research that employed usability-testing technology to analyse cognitive learning processes; personal learning styles and times; and errors-and-recovery of learners using an interactive e-learning tutorial called "Relations." "Relations"…

A non-invasive implementation of a mixed domain decomposition method for frictional contact problems

NASA Astrophysics Data System (ADS)

Oumaziz, Paul; Gosselet, Pierre; Boucard, Pierre-Alain; Guinard, Stéphane

2017-11-01

A non-invasive implementation of the Latin domain decomposition method for frictional contact problems is described. The formulation implies to deal with mixed (Robin) conditions on the faces of the subdomains, which is not a classical feature of commercial software. Therefore we propose a new implementation of the linear stage of the Latin method with a non-local search direction built as the stiffness of a layer of elements on the interfaces. This choice enables us to implement the method within the open source software Code_Aster, and to derive 2D and 3D examples with similar performance as the standard Latin method.

Estimation of the four-wave mixing noise probability-density function by the multicanonical Monte Carlo method.

PubMed

Neokosmidis, Ioannis; Kamalakis, Thomas; Chipouras, Aristides; Sphicopoulos, Thomas

2005-01-01

The performance of high-powered wavelength-division multiplexed (WDM) optical networks can be severely degraded by four-wave-mixing- (FWM-) induced distortion. The multicanonical Monte Carlo method (MCMC) is used to calculate the probability-density function (PDF) of the decision variable of a receiver, limited by FWM noise. Compared with the conventional Monte Carlo method previously used to estimate this PDF, the MCMC method is much faster and can accurately estimate smaller error probabilities. The method takes into account the correlation between the components of the FWM noise, unlike the Gaussian model, which is shown not to provide accurate results.

The Promise of Mixed-Methods for Advancing Latino Health Research

PubMed Central

Apesoa-Varano, Ester Carolina; Hinton, Ladson

2015-01-01

Mixed-methods research in the social sciences has been conducted for quite some time. More recently, mixed-methods have become popular in health research, with the National Institutes of Health leading the impetus to fund studies that implement such an approach. The public health issues facing us today are great and they range from policy and other macro-level issues, to systems level problems to individuals' health behaviors. For Latinos, who are projected to become the largest minority group bearing a great deal of the burden of social inequality in the U.S., it is important to understand the deeply-rooted nature of these health disparities in order to close the gap in health outcomes. Mixed-methodology thus holds promise for advancing research on Latino heath by tackling health disparities from a variety of standpoints and approaches. The aim of this manuscript is to provide two examples of mixed methods research, each of which addresses a health topic of considerable importance to older Latinos and their families. These two examples will illustrate a) the complementary use of qualitative and quantitative methods to advance health of older Latinos in an area that is important from a public health perspective, and b) the “translation” of findings from observational studies (informed by social science and medicine) to the development and testing of interventions. PMID:23996325

Separation of mixed waste plastics via magnetic levitation.

PubMed

Zhao, Peng; Xie, Jun; Gu, Fu; Sharmin, Nusrat; Hall, Philip; Fu, Jianzhong

2018-06-01

Separation becomes a bottleneck of dealing with the enormous stream of waste plastics, as most of the extant methods can only handle binary mixtures. In this paper, a novel method that based on magnetic levitation was proposed for separating multiple mixed plastics. Six types of plastics, i.e., polypropylene (PP), acrylonitrile butadiene styrene (ABS), polyamide 6 (PA6), polycarbonate (PC), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE), were used to simulate the mixed waste plastics. The samples were mixed and immersed into paramagnetic medium that placed into a magnetic levitation configuration with two identical NdFeB magnets with like-poles facing each other, and Fourier transform infrared (FTIR) spectroscopy was employed to verify the separation outputs. Unlike any conventional separation methods such as froth flotation and hydrocyclone, this method is not limited by particle sizes, as mixtures of different size fractions reached their respective equilibrium positions in the initial tests. The two-stage separation tests demonstrated that the plastics can be completely separated with purities reached 100%. The method has the potential to be industrialised into an economically-viable and environmentally-friendly mass production procedure, since quantitative correlations are determined, and the paramagnetic medium can be reused indefinitely. Copyright © 2018 Elsevier Ltd. All rights reserved.

SU-C-207A-05: Feature Based Water Equivalent Path Length (WEPL) Determination for Proton Radiography by the Technique of Time Resolved Dose Measurement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, R; Jee, K; Sharp, G

Purpose: Studies show that WEPL can be determined from modulated dose rate functions (DRF). However, the previous calibration method based on statistics of the DRF is sensitive to energy mixing of protons due to scattering through different materials (termed as range mixing here), causing inaccuracies in the determination of WEPL. This study intends to explore time-domain features of the DRF to reduce the effect of range mixing in proton radiography (pRG) by this technique. Methods: An amorphous silicon flat panel (PaxScan™ 4030CB, Varian Medical Systems, Inc., Palo Alto, CA) was placed behind phantoms to measure DRFs from a proton beammore » modulated by a specially designed modulator wheel. The performance of two methods, the previously used method based on the root mean square (RMS) and the new approach based on time-domain features of the DRF, are compared for retrieving WEPL and RSP from pRG of a Gammex phantom. Results: Calibration by T{sub 80} (the time point for 80% of the major peak) was more robust to range mixing and produced WEPL with improved accuracy. The error of RSP was reduced from 8.2% to 1.7% for lung equivalent material, with the mean error for all other materials reduced from 1.2% to 0.7%. The mean error of the full width at half maximum (FWHM) of retrieved inserts was decreased from 25.85% to 5.89% for the RMS and T{sub 80} method respectively. Monte Carlo simulations in simplified cases also demonstrated that the T{sub 80} method is less sensitive to range mixing than the RMS method. Conclusion: WEPL images have been retrieved based on single flat panel measured DRFs, with inaccuracies reduced by exploiting time-domain features as the calibration parameter. The T{sub 80} method is validated to be less sensitive to range mixing and can thus retrieve the WEPL values in proximity of interfaces with improved numerical and spatial accuracy for proton radiography.« less

A mixed methods approach to assess animal vaccination programmes: The case of rabies control in Bamako, Mali.

PubMed

Mosimann, Laura; Traoré, Abdallah; Mauti, Stephanie; Léchenne, Monique; Obrist, Brigit; Véron, René; Hattendorf, Jan; Zinsstag, Jakob

2017-01-01

In the framework of the research network on integrated control of zoonoses in Africa (ICONZ) a dog rabies mass vaccination campaign was carried out in two communes of Bamako (Mali) in September 2014. A mixed method approach, combining quantitative and qualitative tools, was developed to evaluate the effectiveness of the intervention towards optimization for future scale-up. Actions to control rabies occur on one level in households when individuals take the decision to vaccinate their dogs. However, control also depends on provision of vaccination services and community participation at the intermediate level of social resilience. Mixed methods seem necessary as the problem-driven transdisciplinary project includes epidemiological components in addition to social dynamics and cultural, political and institutional issues. Adapting earlier effectiveness models for health intervention to rabies control, we propose a mixed method assessment of individual effectiveness parameters like availability, affordability, accessibility, adequacy or acceptability. Triangulation of quantitative methods (household survey, empirical coverage estimation and spatial analysis) with qualitative findings (participant observation, focus group discussions) facilitate a better understanding of the weight of each effectiveness determinant, and the underlying reasons embedded in the local understandings, cultural practices, and social and political realities of the setting. Using this method, a final effectiveness of 33% for commune Five and 28% for commune Six was estimated, with vaccination coverage of 27% and 20%, respectively. Availability was identified as the most sensitive effectiveness parameter, attributed to lack of information about the campaign. We propose a mixed methods approach to optimize intervention design, using an "intervention effectiveness optimization cycle" with the aim of maximizing effectiveness. Empirical vaccination coverage estimation is compared to the effectiveness model with its determinants. In addition, qualitative data provide an explanatory framework for deeper insight, validation and interpretation of results which should improve the intervention design while involving all stakeholders and increasing community participation. This work contributes vital information for the optimization and scale-up of future vaccination campaigns in Bamako, Mali. The proposed mixed method, although incompletely applied in this case study, should be applicable to similar rabies interventions targeting elimination in other settings. Copyright © 2016 Elsevier B.V. All rights reserved.

Mixing methodology, nursing theory and research design for a practice model of district nursing advocacy.

PubMed

Reed, Frances M; Fitzgerald, Les; Rae, Melanie

2016-01-01

To highlight philosophical and theoretical considerations for planning a mixed methods research design that can inform a practice model to guide rural district nursing end of life care. Conceptual models of nursing in the community are general and lack guidance for rural district nursing care. A combination of pragmatism and nurse agency theory can provide a framework for ethical considerations in mixed methods research in the private world of rural district end of life care. Reflection on experience gathered in a two-stage qualitative research phase, involving rural district nurses who use advocacy successfully, can inform a quantitative phase for testing and complementing the data. Ongoing data analysis and integration result in generalisable inferences to achieve the research objective. Mixed methods research that creatively combines philosophical and theoretical elements to guide design in the particular ethical situation of community end of life care can be used to explore an emerging field of interest and test the findings for evidence to guide quality nursing practice. Combining philosophy and nursing theory to guide mixed methods research design increases the opportunity for sound research outcomes that can inform a nursing model of care.

Analysis of Academic and Non-Academic Outcomes from a Bottom-up Comprehensive School Reform in the Absence of Student Level Data through Simulation Methods: A Mixed Methods Case Study

ERIC Educational Resources Information Center

Sondergeld, Toni A.

2009-01-01

This dissertation examines the efficacy of a bottom-up comprehensive school reform (CSR) program by evaluating its impact on student achievement, attendance, and behavior outcomes through an explanatory mixed methods design. The CSR program (Gear Up) was implemented in an urban junior high school over the course of seven years allowing for…

Qualitative Methods in Mental Health Services Research

PubMed Central

Palinkas, Lawrence A.

2014-01-01

Qualitative and mixed methods play a prominent role in mental health services research. However, the standards for their use are not always evident, especially for those not trained in such methods. This paper reviews the rationale and common approaches to using qualitative and mixed methods in mental health services and implementation research based on a review of the papers included in this special series along with representative examples from the literature. Qualitative methods are used to provide a “thick description” or depth of understanding to complement breadth of understanding afforded by quantitative methods, elicit the perspective of those being studied, explore issues that have not been well studied, develop conceptual theories or test hypotheses, or evaluate the process of a phenomenon or intervention. Qualitative methods adhere to many of the same principles of scientific rigor as quantitative methods, but often differ with respect to study design, data collection and data analysis strategies. For instance, participants for qualitative studies are usually sampled purposefully rather than at random and the design usually reflects an iterative process alternating between data collection and analysis. The most common techniques for data collection are individual semi-structured interviews, focus groups, document reviews, and participant observation. Strategies for analysis are usually inductive, based on principles of grounded theory or phenomenology. Qualitative methods are also used in combination with quantitative methods in mixed method designs for convergence, complementarity, expansion, development, and sampling. Rigorously applied qualitative methods offer great potential in contributing to the scientific foundation of mental health services research. PMID:25350675

Microencapsulation and Electrostatic Processing Method

NASA Technical Reports Server (NTRS)

Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

2000-01-01

Methods are provided for forming spherical multilamellar microcapsules having alternating hydrophilic and hydrophobic liquid layers, surrounded by flexible, semi-permeable hydrophobic or hydrophilic outer membranes which can be tailored specifically to control the diffusion rate. The methods of the invention rely on low shear mixing and liquid-liquid diffusion process and are particularly well suited for forming microcapsules containing both hydrophilic and hydrophobic drugs. These methods can be carried out in the absence of gravity and do not rely on density-driven phase separation, mechanical mixing or solvent evaporation phases. The methods include the process of forming, washing and filtering microcapsules. In addition, the methods contemplate coating microcapsules with ancillary coatings using an electrostatic field and free fluid electrophoresis of the microcapsules. The microcapsules produced by such methods are particularly useful in the delivery of pharmaceutical compositions.

Least-squares finite element solution of 3D incompressible Navier-Stokes problems

NASA Technical Reports Server (NTRS)

Jiang, Bo-Nan; Lin, Tsung-Liang; Povinelli, Louis A.

1992-01-01

Although significant progress has been made in the finite element solution of incompressible viscous flow problems. Development of more efficient methods is still needed before large-scale computation of 3D problems becomes feasible. This paper presents such a development. The most popular finite element method for the solution of incompressible Navier-Stokes equations is the classic Galerkin mixed method based on the velocity-pressure formulation. The mixed method requires the use of different elements to interpolate the velocity and the pressure in order to satisfy the Ladyzhenskaya-Babuska-Brezzi (LBB) condition for the existence of the solution. On the other hand, due to the lack of symmetry and positive definiteness of the linear equations arising from the mixed method, iterative methods for the solution of linear systems have been hard to come by. Therefore, direct Gaussian elimination has been considered the only viable method for solving the systems. But, for three-dimensional problems, the computer resources required by a direct method become prohibitively large. In order to overcome these difficulties, a least-squares finite element method (LSFEM) has been developed. This method is based on the first-order velocity-pressure-vorticity formulation. In this paper the LSFEM is extended for the solution of three-dimensional incompressible Navier-Stokes equations written in the following first-order quasi-linear velocity-pressure-vorticity formulation.

Effects of mixing procedure itself on the structure, viscosity, and spreadability of white petrolatum and salicylic acid ointment and the skin permeation of salicylic acid.

PubMed

Kitagawa, Shuji; Fujiwara, Megumi; Okinaka, Yuta; Yutani, Reiko; Teraoka, Reiko

2015-01-01

White petrolatum is a mixture of solid and liquid hydrocarbons and its structure can be affected by shear stress. Thus, it might also induce changes in its rheological properties. In this study, we used polarization microscopy to investigate how different mixing methods affect the structure of white petrolatum. We used two different mixing methods, mixing using a rotation/revolution mixer and mixing using an ointment slab and an ointment spatula. The extent of the fragmentation and dispersal of the solid portion of white petrolatum depended on the mixing conditions. Next, we examined the changes in the structure of a salicylic acid ointment, in which white petrolatum was used as a base, induced by mixing and found that the salicylic acid solids within the ointment were also dispersed. In addition to these structural changes, the viscosity and thixotropic behavior of both test substances also decreased in a mixing condition-dependent manner. The reductions in these parameters were most marked after mixing with a rotation/revolution mixer, and similar results were obtained for spreadability. We also investigated the effects of mixing procedure on the skin accumulation and permeation of salicylic acid. They were increased by approximately three-fold after mixing. Little difference in skin accumulation or permeation was detected between the two mixing methods. These findings indicate that mixing procedures themselves affect the utility and physiological effects of white petrolatum-based ointments. Therefore, these effects should be considered when mixing is required for the clinical use of petrolatum-based ointments.

Understanding the Impact of School Factors on School Counselor Burnout: A Mixed-Methods Study

ERIC Educational Resources Information Center

Bardhoshi, Gerta; Schweinle, Amy; Duncan, Kelly

2014-01-01

This mixed-methods study investigated the relationship between burnout and performing noncounseling duties among a national sample of professional school counselors, while identifying school factors that could attenuate this relationship. Results of regression analyses indicate that performing noncounseling duties significantly predicted burnout…

Applying Mixed Methods Techniques in Strategic Planning

ERIC Educational Resources Information Center

Voorhees, Richard A.

2008-01-01

In its most basic form, strategic planning is a process of anticipating change, identifying new opportunities, and executing strategy. The use of mixed methods, blending quantitative and qualitative analytical techniques and data, in the process of assembling a strategic plan can help to ensure a successful outcome. In this article, the author…

A Survey on Chinese Scholars' Adoption of Mixed Methods

ERIC Educational Resources Information Center

Zhou, Yuchun

2018-01-01

Since the 1980s when mixed methods emerged as "the third research methodology", it was widely adopted in Western countries. However, inadequate literature revealed how this methodology was accepted by scholars in Asian countries, such as China. Therefore, this paper used a quantitative survey to investigate Chinese scholars' perceptions…

Asian International Students' Willingness to Seek Counseling: A Mixed-Methods Study

ERIC Educational Resources Information Center

Li, Peiwei; Wong, Y. Joel; Toth, Paul

2013-01-01

Using a mixed-methods survey design that was predominantly quantitative, this study explored Asian international students' willingness to seek counseling. Participants were 177 Asian international students recruited from a U.S. Midwestern University. After controlling for attitudes toward psychological help-seeking and past counseling experience,…

Early Language Learning: Complexity and Mixed Methods

ERIC Educational Resources Information Center

Enever, Janet, Ed.; Lindgren, Eva, Ed.

2017-01-01

This is the first collection of research studies to explore the potential for mixed methods to shed light on foreign or second language learning by young learners in instructed contexts. It brings together recent studies undertaken in Cameroon, China, Croatia, Ethiopia, France, Germany, Italy, Kenya, Mexico, Slovenia, Spain, Sweden, Tanzania and…

Answering the Call: Facilitating Responsive Services for Students Experiencing Homelessness

ERIC Educational Resources Information Center

Grothaus, Tim; Lorelle, Sonya; Anderson, Kie; Knight, Jasmine

2011-01-01

After a review of the literature elucidating the status quo for students experiencing homelessness, this article shares the results of a mixed methods study. With a phenomenological qualitative emphasis, the mixed methods study explored the perceptions of parents and children experiencing homelessness regarding their academic needs and the…

Detecting Low Incidents Effects: The Value of Mixed Methods Research Designs in Low-N Studies

ERIC Educational Resources Information Center

Newman, Isadore; Ridenour, Carolyn S.; Newman, Carole; Smith, Shannon; Brown, Russell C.

2013-01-01

Many important educational situations such as traumatic brain injury among preschoolers, school gun violence, preadolescent eating disorders, and adolescent suicide happen relatively infrequently. In this article, the authors explain why mixed methods research designs offer more meaningful empirical results than do qualitative or quantitative…

Behavioral Changes Based on a Course in Agroecology: A Mixed Methods Study

ERIC Educational Resources Information Center

Harms, Kristyn; King, James; Francis, Charles

2009-01-01

This study evaluated and described student perceptions of a course in agroecology to determine if participants experienced changed perceptions and behaviors resulting from the Agroecosystems Analysis course. A triangulation validating quantitative data mixed methods approach included a written survey comprised of both quantitative and open-ended…

A Typology of Mixed Methods Sampling Designs in Social Science Research

ERIC Educational Resources Information Center

Onwuegbuzie, Anthony J.; Collins, Kathleen M. T.

2007-01-01

This paper provides a framework for developing sampling designs in mixed methods research. First, we present sampling schemes that have been associated with quantitative and qualitative research. Second, we discuss sample size considerations and provide sample size recommendations for each of the major research designs for quantitative and…

Child Geopolitical Agency: A Mixed Methods Case Study

ERIC Educational Resources Information Center

Habashi, Janette; Worley, Jody

2009-01-01

This study examines the geopolitical agency of Palestinian children. Mixed methodology was used to identify the etiologies contributing to processes of political socialization. Both qualitative and qualitative methods are equally distributed throughout this research. Focus groups and interviews with 12 Palestinian children, aged 10 to 13 years,…

The communicative construction of safety in wildland firefighting

Treesearch

Jody Jahn; Linda L. Putnam; Anne E. Black

2012-01-01

This document is a summary of a mixed methods dissertation that examined the communicative construction of safety in wildland firefighting. For the dissertation, I used a two-study mixed methods approach, examining the communicative accomplishment of safety from two perspectives: high reliability organizing (Weick, Sutcliffe, & Obstfeld, 1999), and safety climate (...

The Threat of Unexamined Secondary Data: A Critical Race Transformative Convergent Mixed Methods

ERIC Educational Resources Information Center

Garcia, Nichole M.; Mayorga, Oscar J.

2018-01-01

This article uses a critical race theory framework to conceptualize a Critical Race Transformative Convergent Mixed Methods (CRTCMM) in education. CRTCMM is a methodology that challenges normative educational research practices by acknowledging that racism permeates educational institutions and marginalizes Communities of Color. The focus of this…

A Mixed Learning Approach in Mechatronics Education

ERIC Educational Resources Information Center

Yilmaz, O.; Tuncalp, K.

2011-01-01

This study aims to investigate the effect of a Web-based mixed learning approach model on mechatronics education. The model combines different perception methods such as reading, listening, and speaking and practice methods developed in accordance with the vocational background of students enrolled in the course Electromechanical Systems in…

Asian American College Students' Suicide Ideation: A Mixed-Methods Study

ERIC Educational Resources Information Center

Wong, Y. Joel; Koo, Kelly; Tran, Kimberly K.; Chiu, Yu-Chen; Mok, Yvonne

2011-01-01

The purpose of this mixed-methods study was to explore the phenomenon of suicide ideation among 293 Asian American college students. Guided by T. Joiner's (2005) interpersonal-psychological theory of suicidal behavior, the authors examined the relationships among perceived burdensomeness, thwarted belongingness, self-construals, and suicide…

Contemporary Chinese Parents' Socialization Priorities for Preschoolers: A Mixed Methods Study

ERIC Educational Resources Information Center

Ren, Lixin; Edwards, Carolyn Pope

2016-01-01

This mixed methods study focused on the socialization goals for preschool-aged children among parents from three small-sized cities located in northeastern China. A total of 154 parents with preschool-aged children completed questionnaires measuring parental socialization goals for children's social-emotional competence and academic achievement.…

Support, Belonging, Motivation, and Engagement in the College Classroom: A Mixed Method Study

ERIC Educational Resources Information Center

Zumbrunn, Sharon; McKim, Courtney; Buhs, Eric; Hawley, Leslie R.

2014-01-01

This explanatory sequential mixed methods study examined how belonging perceptions, academic motivation, and engagement might mediate the relationship between academic contextual characteristics and achievement using structural equation modeling and qualitative follow-up interviews with college students from a large, Midwestern university. In the…

Hybrid Learning in Enhancing Communicative Skill in English

ERIC Educational Resources Information Center

Singaravelu, G.

2010-01-01

The present study highlights the effectiveness of Hybrid-Learning in enhancing communicative skill in English among the Trainees of Bachelor of education of School of Distance Education, Bharathiar University,Coimbatore. Hybrid learning refers to mixing of different learning methods or mixing two more methods for teaching learning process. It…

What Do Undergraduate Students Know about Scholarly Communication? A Mixed Methods Study

ERIC Educational Resources Information Center

Riehle, Catherine Fraser; Hensley, Merinda Kaye

2017-01-01

Amid movements that recognize undergraduate students as knowledge creators, transformative work is being done at the intersection of information literacy and scholarly communication. Absent from the literature so far is research related to students' perception and understanding of scholarly communication. This paper reports a mixed methods study…

Using Mixed Methods to Assess Initiatives with Broad-Based Goals

ERIC Educational Resources Information Center

Inkelas, Karen Kurotsuchi

2017-01-01

This chapter describes a process for assessing programmatic initiatives with broad-ranging goals with the use of a mixed-methods design. Using an example of a day-long teaching development conference, this chapter provides practitioners step-by-step guidance on how to implement this assessment process.

Triangulation and Mixed Methods Designs: Data Integration with New Research Technologies

ERIC Educational Resources Information Center

Fielding, Nigel G.

2012-01-01

Data integration is a crucial element in mixed methods analysis and conceptualization. It has three principal purposes: illustration, convergent validation (triangulation), and the development of analytic density or "richness." This article discusses such applications in relation to new technologies for social research, looking at three…

"Comments on Howe": Toward a More Inclusive "Scientific Research in Education"

ERIC Educational Resources Information Center

Johnson, R. Burke

2009-01-01

In response to Howe (2009), the author argues that educational research needs multiple thoughtful perspectives. The author's standpoint is that of a mixed methods research methodologist. Mixed methods research provides an antidualistic and syncretic philosophy and set of approaches or possibilities for merging insights from diverse perspectives;…

Being Outside Learning about Science Is Amazing: A Mixed Methods Study

ERIC Educational Resources Information Center

Weibel, Michelle L.

2011-01-01

This study used a convergent parallel mixed methods design to examine teachers' environmental attitudes and concerns about an outdoor educational field trip. Converging both quantitative data (Environmental Attitudes Scale and teacher demographics) and qualitative data (Open-Ended Statements of Concern and interviews) facilitated interpretation.…

Teacher Perceptions of Principals' Leadership Qualities: A Mixed Methods Study

ERIC Educational Resources Information Center

Hauserman, Cal P.; Ivankova, Nataliya V.; Stick, Sheldon L.

2013-01-01

This mixed methods sequential explanatory study utilized the Multi-factor Leadership Questionnaire, responses to open-ended questions, and in-depth interviews to identify transformational leadership qualities that were present among principals in Alberta, Canada. The first quantitative phase consisted of a random sample of 135 schools (with…

Mixed methods analysis of urban environmental stewardship networks

Treesearch

James J.T. Connolly; Erika S. Svendsen; Dana R. Fisher; Lindsay K. Campbell

2015-01-01

While mixed methods approaches to research have been accepted practice within the social sciences for several decades (Tashakkori and Teddlie 2003), the rising demand for cross-disciplinary analyses of socio-environmental processes has necessitated a renewed examination of this approach within environmental studies. Urban environmental stewardship is one area where it...

Do Different Training Conditions Facilitate Team Implementation? A Quasi-Experimental Mixed Methods Study

ERIC Educational Resources Information Center

Nielsen, Karina; Randall, Raymond; Christensen, Karl B.

2017-01-01

A mixed methods approach was applied to examine the effects of a naturally occurring teamwork intervention supported with training. The first objective was to integrate qualitative process evaluation and quantitative effect evaluation to examine "how" and "why" the training influence intervention outcomes. The intervention (N =…

Students' Attitudes toward Statistics across the Disciplines: A Mixed-Methods Approach

ERIC Educational Resources Information Center

Griffith, James D.; Adams, Lea T.; Gu, Lucy L.; Hart, Christian L.; Nichols-Whitehead, Penney

2012-01-01

Students' attitudes toward statistics were investigated using a mixed-methods approach including a discovery-oriented qualitative methodology among 684 undergraduate students across business, criminal justice, and psychology majors where at least one course in statistics was required. Students were asked about their attitudes toward statistics and…

Basic investigation of the laminated alginate impression technique: Setting time, permanent deformation, elastic deformation, consistency, and tensile bond strength tests.

PubMed

Kitamura, Aya; Kawai, Yasuhiko

2015-01-01

Laminated alginate impression for edentulous is simple and time efficient compared to border molding technique. The purpose of this study was to examine clinical applicability of the laminated alginate impression, by measuring the effects of different Water/Powder (W/P) and mixing methods, and different bonding methods in the secondary impression of alginate impression. Three W/P: manufacturer-designated mixing water amount (standard), 1.5-fold (1.5×) and 1.75-fold (1.75×) water amount were mixed by manual and automatic mixing methods. Initial and complete setting time, permanent and elastic deformation, and consistency of the secondary impression were investigated (n=10). Additionally, tensile bond strength between the primary and secondary impression were measured in the following surface treatment; air blow only (A), surface baking (B), and alginate impression material bonding agent (ALGI-BOND: AB) (n=12). Initial setting times significantly shortened with automatic mixing for all W/P (p<0.05). The permanent deformation decreased and elastic deformation increased as high W/P, regardless of the mixing method. Elastic deformation significantly reduced in 1.5× and 1.75× with automatic mixing (p<0.05). All of these properties resulted within JIS standards. For all W/P, AB showed a significantly high bonding strength as compared to A and B (p<0.01). The increase of mixing water, 1.5× and 1.75×, resulted within JIS standards in setting time, suggesting its applicability in clinical setting. The use of automatic mixing device decreased elastic strain and shortening of the curing time. For the secondary impression application of adhesives on the primary impression gives secure adhesion. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Comparison of Minimally and More Invasive Methods of Determining Mixed Venous Oxygen Saturation.

PubMed

Smit, Marli; Levin, Andrew I; Coetzee, Johan F

2016-04-01

To investigate the accuracy of a minimally invasive, 2-step, lookup method for determining mixed venous oxygen saturation compared with conventional techniques. Single-center, prospective, nonrandomized, pilot study. Tertiary care hospital, university setting. Thirteen elective cardiac and vascular surgery patients. All participants received intra-arterial and pulmonary artery catheters. Minimally invasive oxygen consumption and cardiac output were measured using a metabolic module and lithium-calibrated arterial waveform analysis (LiDCO; LiDCO, London), respectively. For the minimally invasive method, Step 1 involved these minimally invasive measurements, and arterial oxygen content was entered into the Fick equation to calculate mixed venous oxygen content. Step 2 used an oxyhemoglobin curve spreadsheet to look up mixed venous oxygen saturation from the calculated mixed venous oxygen content. The conventional "invasive" technique used pulmonary artery intermittent thermodilution cardiac output, direct sampling of mixed venous and arterial blood, and the "reverse-Fick" method of calculating oxygen consumption. LiDCO overestimated thermodilution cardiac output by 26%. Pulmonary artery catheter-derived oxygen consumption underestimated metabolic module measurements by 27%. Mixed venous oxygen saturation differed between techniques; the calculated values underestimated the direct measurements by between 12% to 26.3%, this difference being statistically significant. The magnitude of the differences between the minimally invasive and invasive techniques was too great for the former to act as a surrogate of the latter and could adversely affect clinical decision making. Copyright © 2016 Elsevier Inc. All rights reserved.

Is verbatim transcription of interview data always necessary?

PubMed

Halcomb, Elizabeth J; Davidson, Patricia M

2006-02-01

Verbatim transcription of interview data has become a common data management strategy in nursing research and is widely considered to be integral to the analysis and interpretation of verbal data. As the benefits of verbal data are becoming more widely embraced in health care research, interviews are being increasingly used to collect information for a wide range of purposes. In addition to purely qualitative investigations, there has been a significant increase in the conduct of mixed-method inquiries. This article examines the issues surrounding the conduct of interviews in mixed-method research, with particular emphasis on the transcription and data analysis phases of data management. It also debates on the necessity to transcribe all audiorecorded interview data verbatim, particularly in relation to mixed-method investigations. Finally, it provides an alternative method to verbatim transcription of managing audiorecorded interview data.

Precise determination of lattice phase shifts and mixing angles

DOE PAGES

Lu, Bing -Nan; Lähde, Timo A.; Lee, Dean; ...

2016-07-09

Here, we introduce a general and accurate method for determining lattice phase shifts and mixing angles, which is applicable to arbitrary, non-cubic lattices. Our method combines angular momentum projection, spherical wall boundaries and an adjustable auxiliary potential. This allows us to construct radial lattice wave functions and to determine phase shifts at arbitrary energies. For coupled partial waves, we use a complex-valued auxiliary potential that breaks time-reversal invariance. We benchmark our method using a system of two spin-1/2 particles interacting through a finite-range potential with a strong tensor component. We are able to extract phase shifts and mixing angles formore » all angular momenta and energies, with precision greater than that of extant methods. We discuss a wide range of applications from nuclear lattice simulations to optical lattice experiments.« less

Adding Qualitative and Mixed Methods Research to Health Intervention Studies: Interacting With Differences.

PubMed

Johnson, R Burke; Schoonenboom, Judith

2016-04-01

The purpose of this article is to explain how to improve intervention designs, such as randomized controlled trials (RCTs), in health science research using a process philosophy and theory known as dialectical pluralism (DP). DP views reality as plural and uses dialectical, dialogical, and hermeneutical approaches to knowledge construction. Using DP and its "both/and" logic, and its attempt to produce new creative syntheses, researchers on heterogeneous teams can better dialogue with qualitative and mixed methods approaches, concepts, paradigms, methodologies, and methods to improve their intervention research studies. The concept of reflexivity is utilized but is expanded when it is a component of DP. Examples of strategies for identifying, inviting, and creating divergence and integrative strategies for producing strong mixed methods intervention studies are provided and illustrated using real-life examples. © The Author(s) 2015.

Costing complexities in mixed apheresis.

PubMed

Trenchard, P M

1993-07-01

For mixed apheresis procedures {plasma (PMA) and platelets (PLTs) as products}, six cost-accounting methods are described for apportioning the unit procedure cost ($156.02; representative example) to the two products. The methods are derived from clinical/scientific apheresis principles, but provide a wide range of unit PLT costs ($14.10, 19.71, 34.37, 42.06, 43.82 and 52.00) which relate inversely to the corresponding unit PMA costs ($73.84, 63.01, 34.36, 19.37, 15.94 and 0.00). Two of the methods appear particularly appropriate, depending upon whether the procedure is driven by PLTs predominantly or by PMA+PLTs equally. The paper encourages apheresis physicians and scientists to debate the relative attributes of the methods, develop refinements of the same, and determine through dialogue that mixed apheresis costing models properly account for the clinical science of the service provided.

The effect of different methods to compute N on estimates of mixing in stratified flows

NASA Astrophysics Data System (ADS)

Fringer, Oliver; Arthur, Robert; Venayagamoorthy, Subhas; Koseff, Jeffrey

2017-11-01

The background stratification is typically well defined in idealized numerical models of stratified flows, although it is more difficult to define in observations. This may have important ramifications for estimates of mixing which rely on knowledge of the background stratification against which turbulence must work to mix the density field. Using direct numerical simulation data of breaking internal waves on slopes, we demonstrate a discrepancy in ocean mixing estimates depending on the method in which the background stratification is computed. Two common methods are employed to calculate the buoyancy frequency N, namely a three-dimensionally resorted density field (often used in numerical models) and a locally-resorted vertical density profile (often used in the field). We show that how N is calculated has a significant effect on the flux Richardson number Rf, which is often used to parameterize turbulent mixing, and the turbulence activity number Gi, which leads to errors when estimating the mixing efficiency using Gi-based parameterizations. Supported by ONR Grant N00014-08-1-0904 and LLNL Contract DE-AC52-07NA27344.

MIXOPTIM: A tool for the evaluation and the optimization of the electricity mix in a territory

NASA Astrophysics Data System (ADS)

Bonin, Bernard; Safa, Henri; Laureau, Axel; Merle-Lucotte, Elsa; Miss, Joachim; Richet, Yann

2014-09-01

This article presents a method of calculation of the generation cost of a mixture of electricity sources, by means of a Monte Carlo simulation of the production output taking into account the fluctuations of the demand and the stochastic nature of the availability of the various power sources that compose the mix. This evaluation shows that for a given electricity mix, the cost has a non-linear dependence on the demand level. In the second part of the paper, we develop some considerations on the management of intermittence. We develop a method based on spectral decomposition of the imposed power fluctuations to calculate the minimal amount of the controlled power sources needed to follow these fluctuations. This can be converted into a viability criterion of the mix included in the MIXOPTIM software. In the third part of the paper, the MIXOPTIM cost evaluation method is applied to the multi-criteria optimization of the mix, according to three main criteria: the cost of the mix; its impact on climate in terms of CO2 production; and the security of supply.

Simulation of Reacting Flow with a Discontinuous Spectral Element Method

NASA Astrophysics Data System (ADS)

Ghiasi, Zia; Mashayek, Farzad; Komperda, Jonathan

2013-11-01

While using high order methods is desirable in order to accurately capture the small scale mixing effects in reacting flows, the challenge is to develop and implement such methods for complex geometries. In this work, a high-order Discontinuous Spectral Element Method (DSEM) code, which solves for the Navier-Stokes equations, has been modified by adding the appropriate components to solve for scalar transport equations in order to simulate the chemical reaction. Dealing with discontinuous solution at element interfaces is a challenge that is met by patching the fluxes at mortars thus making them continuous on interfaces. The patching is performed using the Lax-Fredrichs numerical flux for scalars, whereas a generalized Riemann solver is used for the Navier-Stokes equations. Direct numerical simulation is conducted in a temporally developing mixing layer to validate the method for a single step reaction (F + rO --> [ 1 + r ] P). Next, the method is implemented to simulate a subsonic reacting flow in a slanted cavity combustor with gaseous fuel injectors to demonstrate the capability of the method to handle complex geometries. The results will be used for physical understanding of mixing and reaction in this type of combustors.

A Unified Development of Basis Reduction Methods for Rotor Blade Analysis

NASA Technical Reports Server (NTRS)

Ruzicka, Gene C.; Hodges, Dewey H.; Rutkowski, Michael (Technical Monitor)

2001-01-01

The axial foreshortening effect plays a key role in rotor blade dynamics, but approximating it accurately in reduced basis models has long posed a difficult problem for analysts. Recently, though, several methods have been shown to be effective in obtaining accurate,reduced basis models for rotor blades. These methods are the axial elongation method,the mixed finite element method, and the nonlinear normal mode method. The main objective of this paper is to demonstrate the close relationships among these methods, which are seemingly disparate at first glance. First, the difficulties inherent in obtaining reduced basis models of rotor blades are illustrated by examining the modal reduction accuracy of several blade analysis formulations. It is shown that classical, displacement-based finite elements are ill-suited for rotor blade analysis because they can't accurately represent the axial strain in modal space, and that this problem may be solved by employing the axial force as a variable in the analysis. It is shown that the mixed finite element method is a convenient means for accomplishing this, and the derivation of a mixed finite element for rotor blade analysis is outlined. A shortcoming of the mixed finite element method is that is that it increases the number of variables in the analysis. It is demonstrated that this problem may be rectified by solving for the axial displacements in terms of the axial forces and the bending displacements. Effectively, this procedure constitutes a generalization of the widely used axial elongation method to blades of arbitrary topology. The procedure is developed first for a single element, and then extended to an arbitrary assemblage of elements of arbitrary type. Finally, it is shown that the generalized axial elongation method is essentially an approximate solution for an invariant manifold that can be used as the basis for a nonlinear normal mode.

A general method to determine sampling windows for nonlinear mixed effects models with an application to population pharmacokinetic studies.

PubMed

Foo, Lee Kien; McGree, James; Duffull, Stephen

2012-01-01

Optimal design methods have been proposed to determine the best sampling times when sparse blood sampling is required in clinical pharmacokinetic studies. However, the optimal blood sampling time points may not be feasible in clinical practice. Sampling windows, a time interval for blood sample collection, have been proposed to provide flexibility in blood sampling times while preserving efficient parameter estimation. Because of the complexity of the population pharmacokinetic models, which are generally nonlinear mixed effects models, there is no analytical solution available to determine sampling windows. We propose a method for determination of sampling windows based on MCMC sampling techniques. The proposed method attains a stationary distribution rapidly and provides time-sensitive windows around the optimal design points. The proposed method is applicable to determine sampling windows for any nonlinear mixed effects model although our work focuses on an application to population pharmacokinetic models. Copyright © 2012 John Wiley & Sons, Ltd.

Consideration of reinforcement mechanism in the short fiber mixing granular materials by granular element simulations

NASA Astrophysics Data System (ADS)

Mori, Kentaro; Kaneko, Kenji; Hashizume, Yutaka

2017-06-01

The short fiber mixing method is well known as one of the method to improve the strength of gran- ular soils in geotechnical engineering. Mechanical properties of the short fiber mixing granular materials are influenced by many factors, such as the mixture ratio of the short fiber, the material of short fiber, the length, and the orientation. In particular, the mixture ratio of the short fibers is very important in mixture design. In the past study, we understood that the strength is reduced by too much short fiber mixing by a series of tri-axial compression experiments. Namely, there is "optimum mixture ratio" in the short fiber mixing granular soils. In this study, to consider the mechanism of occurrence of the optimum mixture ratio, we carried out the numerical experiments by granular element method. As the results, we can understand that the strength decrease when too much grain-fiber contact points exist, because a friction coefficient is smaller than the grain-grain contact points.

MixSIAR: advanced stable isotope mixing models in R

EPA Science Inventory

Background/Question/Methods The development of stable isotope mixing models has coincided with modeling products (e.g. IsoSource, MixSIR, SIAR), where methodological advances are published in parity with software packages. However, while mixing model theory has recently been ex...

Situating and Constructing Diversity in Semi-Structured Interviews

PubMed Central

McIntosh, Michele J.; Morse, Janice M.

2015-01-01

Although semi-structured interviews (SSIs) are used extensively in research, scant attention is given to their diversity, underlying assumptions, construction, and broad applications to qualitative and mixed-method research. In this three-part article, we discuss the following: (a) how the SSI is situated historically including its evolution and diversification, (b) the principles of constructing SSIs, and (c) how SSIs are utilized as a stand-alone research method, and as strategy within a mixed-method design. PMID:28462313

Effect of composition and calcination temperature of ceria-zirconia-alumina mixed oxides on catalytic performances of ethanol conversion

NASA Astrophysics Data System (ADS)

Chuklina, S. G.; Maslenkova, S. A.; Pylinina, A. I.; Podzorova, L. I.; Ilyicheva, A. A.

2017-02-01

In the present study, we investigated the effect of preparation method, phase composition and calcination temperature of the (Ce-TZP) - Al2O3 mixed oxides on their structural features and catalytic performance in ethanol conversion. Ceria-zirconia-alumina mixed oxides with different (Ce+Zr)/Al atomic ratios were prepared via sol-gel method. Catalytic activity and selectivity were investigated for ethanol conversion to acetaldehyde, ethylene and diethyl ether.

Monitoring total mixed rations and feed delivery systems.

PubMed

Oelberg, Thomas J; Stone, William

2014-11-01

This article is intended to give practitioners a method to evaluate total mixed ration (TMR) consistency and to give them practical solutions to improve TMR consistency that will improve cattle performance and health. Practitioners will learn how to manage the variation in moisture and nutrients that exists in haylage and corn silage piles and in bales of hay, and methods to reduce variation in the TMR mixing and delivery process. Copyright © 2014 Elsevier Inc. All rights reserved.

Approaching Etuaptmumk--introducing a consensus-based mixed method for health services research.

PubMed

Chatwood, Susan; Paulette, Francois; Baker, Ross; Eriksen, Astrid; Hansen, Ketil Lenert; Eriksen, Heidi; Hiratsuka, Vanessa; Lavoie, Josée; Lou, Wendy; Mauro, Ian; Orbinski, James; Pabrum, Nathalie; Retallack, Hanna; Brown, Adalsteinn

2015-01-01

With the recognized need for health systems' improvements in the circumpolar and indigenous context, there has been a call to expand the research agenda across all sectors influencing wellness and to recognize academic and indigenous knowledge through the research process. Despite being recognized as a distinct body of knowledge in international forums and across indigenous groups, examples of methods and theories based on indigenous knowledge are not well documented in academic texts or peer-reviewed literature on health systems. This paper describes the use of a consensus-based, mixed method with indigenous knowledge by an experienced group of researchers and indigenous knowledge holders who collaborated on a study that explored indigenous values underlying health systems stewardship. The method is built on the principles of Etuaptmumk or two-eyed seeing, which aim to respond to and resolve the inherent conflicts between indigenous ways of knowing and the scientific inquiry that informs the evidence base in health care. Mixed methods' frameworks appear to provide a framing suitable for research questions that require data from indigenous knowledge sources and western knowledge. The nominal consensus method, as a western paradigm, was found to be responsive to embedding of indigenous knowledge and allowed space to express multiple perspectives and reach consensus on the question at hand. Further utilization and critical evaluation of this mixed methodology with indigenous knowledge are required.

Parameter sensitivity analysis of the mixed Green-Ampt/Curve-Number method for rainfall excess estimation in small ungauged catchments

NASA Astrophysics Data System (ADS)

Romano, N.; Petroselli, A.; Grimaldi, S.

2012-04-01

With the aim of combining the practical advantages of the Soil Conservation Service - Curve Number (SCS-CN) method and Green-Ampt (GA) infiltration model, we have developed a mixed procedure, which is referred to as CN4GA (Curve Number for Green-Ampt). The basic concept is that, for a given storm, the computed SCS-CN total net rainfall amount is used to calibrate the soil hydraulic conductivity parameter of the Green-Ampt model so as to distribute in time the information provided by the SCS-CN method. In a previous contribution, the proposed mixed procedure was evaluated on 100 observed events showing encouraging results. In this study, a sensitivity analysis is carried out to further explore the feasibility of applying the CN4GA tool in small ungauged catchments. The proposed mixed procedure constrains the GA model with boundary and initial conditions so that the GA soil hydraulic parameters are expected to be insensitive toward the net hyetograph peak. To verify and evaluate this behaviour, synthetic design hyetograph and synthetic rainfall time series are selected and used in a Monte Carlo analysis. The results are encouraging and confirm that the parameter variability makes the proposed method an appropriate tool for hydrologic predictions in ungauged catchments. Keywords: SCS-CN method, Green-Ampt method, rainfall excess, ungauged basins, design hydrograph, rainfall-runoff modelling.

Acoustic⁻Seismic Mixed Feature Extraction Based on Wavelet Transform for Vehicle Classification in Wireless Sensor Networks.

PubMed

Zhang, Heng; Pan, Zhongming; Zhang, Wenna

2018-06-07

An acoustic⁻seismic mixed feature extraction method based on the wavelet coefficient energy ratio (WCER) of the target signal is proposed in this study for classifying vehicle targets in wireless sensor networks. The signal was decomposed into a set of wavelet coefficients using the à trous algorithm, which is a concise method used to implement the wavelet transform of a discrete signal sequence. After the wavelet coefficients of the target acoustic and seismic signals were obtained, the energy ratio of each layer coefficient was calculated as the feature vector of the target signals. Subsequently, the acoustic and seismic features were merged into an acoustic⁻seismic mixed feature to improve the target classification accuracy after the acoustic and seismic WCER features of the target signal were simplified using the hierarchical clustering method. We selected the support vector machine method for classification and utilized the data acquired from a real-world experiment to validate the proposed method. The calculated results show that the WCER feature extraction method can effectively extract the target features from target signals. Feature simplification can reduce the time consumption of feature extraction and classification, with no effect on the target classification accuracy. The use of acoustic⁻seismic mixed features effectively improved target classification accuracy by approximately 12% compared with either acoustic signal or seismic signal alone.

Travel into a fairy land: a critique of modern qualitative and mixed methods psychologies.

PubMed

Toomela, Aaro

2011-03-01

In this article modern qualitative and mixed methods approaches are criticized from the standpoint of structural-systemic epistemology. It is suggested that modern qualitative methodologies suffer from several fallacies: some of them are grounded on inherently contradictory epistemology, the others ask scientific questions after the methods have been chosen, conduct studies inductively so that not only answers but even questions are often supposed to be discovered, do not create artificial situations and constraints on study-situations, are adevelopmental by nature, study not the external things and phenomena but symbols and representations--often the object of studies turns out to be the researcher rather than researched, rely on ambiguous data interpretation methods based to a large degree on feelings and opinions, aim to understand unique which is theoretically impossible, or have theoretical problems with sampling. Any one of these fallacies would be sufficient to exclude any possibility to achieve structural-systemic understanding of the studied things and phenomena. It also turns out that modern qualitative methodologies share several fallacies with the quantitative methodology. Therefore mixed methods approaches are not able to overcome the fundamental difficulties that characterize mixed methods taken separately. It is proposed that structural-systemic methodology that dominated psychological thought in the pre-WWII continental Europe is philosophically and theoretically better grounded than the other methodologies that can be distinguished in psychology today. Future psychology should be based on structural-systemic methodology.

Method of analysis for compressible flow through mixed-flow centrifugal impellers of arbitrary design

NASA Technical Reports Server (NTRS)

Hamrick, Joseph T; Ginsburg, Ambrose; Osborn, Walter M

1952-01-01

A method is presented for analysis of the compressible flow between the hub and the shroud of mixed-flow impellers of arbitrary design. Axial symmetry was assumed, but the forces in the meridional (hub to shroud) plane, which are derived from tangential pressure gradients, were taken into account. The method was applied to an experimental mixed-flow impeller. The analysis of the flow in the meridional plane of the impeller showed that the rotational forces, the blade curvature, and the hub-shroud profile can introduce severe velocity gradients along the hub and the shroud surfaces. Choked flow at the impeller inlet as determined by the analysis was verified by experimental results.

An equivalent method of mixed dielectric constant in passive microwave/millimeter radiometric measurement

NASA Astrophysics Data System (ADS)

Su, Jinlong; Tian, Yan; Hu, Fei; Gui, Liangqi; Cheng, Yayun; Peng, Xiaohui

2017-10-01

Dielectric constant is an important role to describe the properties of matter. This paper proposes This paper proposes the concept of mixed dielectric constant(MDC) in passive microwave radiometric measurement. In addition, a MDC inversion method is come up, Ratio of Angle-Polarization Difference(RAPD) is utilized in this method. The MDC of several materials are investigated using RAPD. Brightness temperatures(TBs) which calculated by MDC and original dielectric constant are compared. Random errors are added to the simulation to test the robustness of the algorithm. Keywords: Passive detection, microwave/millimeter, radiometric measurement, ratio of angle-polarization difference (RAPD), mixed dielectric constant (MDC), brightness temperatures, remote sensing, target recognition.

Rapid and efficient mixing in a slip-driven three-dimensional flow in a rectangular channel

NASA Astrophysics Data System (ADS)

Pacheco, J. Rafael; Ping Chen, Kang; Hayes, Mark A.

2006-08-01

A method for generating mixing in an electroosmotic flow of an electrolytic solution in a three-dimensional channel is proposed. When the width-to-height aspect ratio of the channel cross-section is large, mixing of a blob of a solute in a slip-driven three-dimensional flow in a rectangular channel can be used to model and assess the effectiveness of this method. It is demonstrated through numerical simulations that under certain operating conditions, rapid and efficient mixing can be achieved. Future investigation will include the solution of the exact equations and experimentation.

Estimation of the mixing layer height over a high altitude site in Central Himalayan region by using Doppler lidar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shukla, K. K.; Phanikumar, D. V.; Newsom, Rob K.

2014-03-01

A Doppler lidar was installed at Manora Peak, Nainital (29.4 N; 79.2 E, 1958 amsl) to estimate mixing layer height for the first time by using vertical velocity variance as basic measurement parameter for the period September-November 2011. Mixing layer height is found to be located ~0.57 +/- 0.1and 0.45 +/- 0.05km AGL during day and nighttime, respectively. The estimation of mixing layer height shows good correlation (R>0.8) between different instruments and with different methods. Our results show that wavelet co-variance transform is a robust method for mixing layer height estimation.

Exploring the Characteristics of Professional Learning Communities in China: A Mixed-Method Study

ERIC Educational Resources Information Center

Zhang, Jia; Pang, Nicholas Sun-Keung

2016-01-01

This mixed-method study explored the characteristics of professional learning communities (PLCs) in Chinese schools. Informed by the existing literature on PLCs, the authors conducted a questionnaire survey of teachers in seven schools in Shanghai to explore the characteristics of Chinese PLCs. Follow-up qualitative interviews were also conducted…

Self-Efficacy and Preparation of Scholarly Writing: Online Doctoral Coursework to Comprehensive Examination--a Mixed Method Study

ERIC Educational Resources Information Center

Thomas, Sonya C.

2013-01-01

Writing is seldom explicitly taught, most specifically, in academic and scholarly writing. Therefore, this mixed methods correlational phenomenology research study explored the correlation between self-efficacy perception and course room preparation for the comprehensive examination, APA standards in the course room, APA standards evaluation for…

From Ethnography to Items: A Mixed Methods Approach to Developing a Survey to Examine Graduate Engineering Student Retention

ERIC Educational Resources Information Center

Crede, Erin; Borrego, Maura

2013-01-01

As part of a sequential exploratory mixed methods study, 9 months of ethnographically guided observations and interviews were used to develop a survey examining graduate engineering student retention. Findings from the ethnographic fieldwork yielded several themes, including international diversity, research group organization and climate,…

Exploring Intercultural Sensitivity in Early Adolescence: A Mixed Methods Study

ERIC Educational Resources Information Center

Mellizo, Jennifer M.

2017-01-01

The purpose of this mixed methods study was to explore levels of intercultural sensitivity in a sample of fourth to eighth grade students in the United States (n = 162). "Intercultural sensitivity" was conceptualised through Bennett's Developmental Model of Sensitivity, and assessed through the Adapted Intercultural Sensitivity Index.…

Applying the Mixed Methods Instrument Development and Construct Validation Process: the Transformative Experience Questionnaire

ERIC Educational Resources Information Center

Koskey, Kristin L. K.; Sondergeld, Toni A.; Stewart, Victoria C.; Pugh, Kevin J.

2018-01-01

Onwuegbuzie and colleagues proposed the Instrument Development and Construct Validation (IDCV) process as a mixed methods framework for creating and validating measures. Examples applying IDCV are lacking. We provide an illustrative case integrating the Rasch model and cognitive interviews applied to the development of the Transformative…

Innovative Mixed-Methods Research: Moving beyond Design Technicalities to Epistemological and Methodological Realizations

ERIC Educational Resources Information Center

Riazi, A. Mehdi

2016-01-01

Mixed-methods research (MMR), as an inter-discourse (quantitative and qualitative) methodology, can provide applied linguistics researchers the opportunity to draw on and integrate the strengths of the two research methodological approaches in favour of making more rigorous inferences about research problems. In this article, the argument is made…

A Study on the Spatial Abilities of Prospective Social Studies Teachers: A Mixed Method Research

ERIC Educational Resources Information Center

Yurt, Eyüp; Tünkler, Vural

2016-01-01

This study investigated prospective social studies teachers' spatial abilities. It was conducted with 234 prospective teachers attending Social Studies Teaching departments at Education Faculties of two universities in Central and Southern Anatolia. This study, designed according to the explanatory-sequential design, is a mixed research method,…

Preservice Teachers' Perceptions of Quality in Online Education Courses: A Mixed Methods Examination

ERIC Educational Resources Information Center

McCormick Myers, Myrell Denice

2012-01-01

The purpose of this mixed methods study was to examine preservice teacher education candidates' perceptions of quality in online education courses within a regional comprehensive university located in Texas. The research questions also addressed students' perceived efficacy in their level of preparedness to: engage in field experiences;…

Assessing the Effectiveness of "Wise Guys": A Mixed-Methods Approach

ERIC Educational Resources Information Center

Herrman, Judith W.; Gordon, Mellissa; Rahmer, Brian; Moore, Christopher C.; Habermann, Barbara; Haigh, Katherine M.

2017-01-01

Previous research raised questions on the validity of survey studies with the teen population. As one response, our team implemented a mixed-methods study to evaluate an evidence-based, interactive curriculum, "Wise Guys," which is designed to promote healthy relationships and sexual behavior in young men ages 4-17. The current study…

An Observational Analysis of Coaching Behaviors for Career Development Event Teams: A Mixed Methods Study

ERIC Educational Resources Information Center

Ball, Anna L.; Bowling, Amanda M.; Sharpless, Justin D.

2016-01-01

School Based Agricultural Education (SBAE) teachers can use coaching behaviors, along with their agricultural content knowledge to help their Career Development Event (CDE) teams succeed. This mixed methods, collective case study observed three SBAE teachers preparing multiple CDEs throughout the CDE season. The teachers observed had a previous…

Acceptability of School-Based Health Centers for Human Papillomavirus Vaccination Visits: A Mixed-Methods Study

ERIC Educational Resources Information Center

Hansen, Caitlin E.; Okoloko, Edirin; Ogunbajo, Adedotun; North, Anna; Niccolai, Linda M.

2017-01-01

Background: Countries with high human papillomavirus (HPV) vaccination rates have achieved this success largely through school-based vaccination. Using school-based health centers (SBHCs) in the United States, where HPV vaccine remains underutilized, could improve uptake. In this mixed-methods study, we examined acceptability, facilitators, and…

Understanding Student Stress and Coping in Elementary School: A Mixed-Method, Longitudinal Study

ERIC Educational Resources Information Center

Sotardi, Valerie A.

2016-01-01

This mixed-method, longitudinal study examined daily school stress and coping strategies of elementary schoolchildren in the United States. Students (n = 65) between the ages of 7 and 11 years reported daily school stress measures for 8 weeks and completed individual stress and coping interviews. Results highlight critical relations between…

Words Speak Louder than Action?: A Mixed-Methods Case Study

ERIC Educational Resources Information Center

Vincent, Stacy K.; Kirby, Andrea T.

2015-01-01

The purpose of this mixed-methods case study was to examine the dynamic of Culturally Responsive Pedagogy (Gay, 2010) among nine secondary agriculture teachers in ethnically diverse schools. By reviewing the diversity of student enrollment in the agriculture programs, the participants were separated by two groups: diverse and non-diverse. A hybrid…

Scaffolding Argumentation about Water Quality: A Mixed-Method Study in a Rural Middle School

ERIC Educational Resources Information Center

Belland, Brian R.; Gu, Jiangyue; Armbrust, Sara; Cook, Brant

2015-01-01

A common way for students to develop scientific argumentation abilities is through argumentation about socioscientific issues, defined as scientific problems with social, ethical, and moral aspects. Computer-based scaffolding can support students in this process. In this mixed method study, we examined the use and impact of computer based…

76 FR 22735 - Shaw AREVA MOX Services, Mixed Oxide Fuel Fabrication Facility; License Amendment Request, Notice...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-22

... NUCLEAR REGULATORY COMMISSION [Docket No. 70-3098; NRC-2011-0081] Shaw AREVA MOX Services, Mixed... following methods: Federal Rulemaking Web site: Go to http://www.regulations.gov and search for documents... publicly available documents related to this notice using the following methods: NRC's Public Document Room...

Validity Argument for Assessing L2 Pragmatics in Interaction Using Mixed Methods

ERIC Educational Resources Information Center

Youn, Soo Jung

2015-01-01

This study investigates the validity of assessing L2 pragmatics in interaction using mixed methods, focusing on the evaluation inference. Open role-plays that are meaningful and relevant to the stakeholders in an English for Academic Purposes context were developed for classroom assessment. For meaningful score interpretations and accurate…

Engineers' Perceptions of Diversity and the Learning Environment at Work: A Mixed Methods Study

ERIC Educational Resources Information Center

Firestone, Brenda L.

2012-01-01

The purpose of this dissertation research study was to investigate engineers' perceptions of diversity and the workplace learning environment surrounding diversity education efforts in engineering occupations. The study made use of a mixed methods methodology and was theoretically framed using a critical feminist adult education lens and…

Next Generation Science Standards: A National Mixed-Methods Study on Teacher Readiness

ERIC Educational Resources Information Center

Haag, Susan; Megowan, Colleen

2015-01-01

Next Generation Science Standards (NGSS) science and engineering practices are ways of eliciting the reasoning and applying foundational ideas in science. As research has revealed barriers to states and schools adopting the NGSS, this mixed-methods study attempts to identify characteristics of professional development (PD) that will support NGSS…

Mixed Methods Research: What Are the Key Issues to Consider?

ERIC Educational Resources Information Center

Ghosh, Rajashi

2016-01-01

Mixed methods research (MMR) is increasingly becoming a popular methodological approach in several fields due to the promise it holds for comprehensive understanding of complex problems being researched. However, researchers interested in MMR often lack reference to a guide that can explain the key issues pertaining to the paradigm wars…

Understanding Succession Planning and Management Efforts at Midwestern University: A Mixed Methods Study

ERIC Educational Resources Information Center

Mateso, Peter E. E.

2010-01-01

The purpose of this concurrent triangulation mixed methods study was to understand the status of succession planning and management (SPM) efforts of the subject university as perceived by the fulltime academic and fulltime administrative staff. Four research questions guided this study: (1) how do fulltime academic staff and fulltime…

Visual Tools for Eliciting Connections and Cohesiveness in Mixed Methods Research

ERIC Educational Resources Information Center

Murawska, Jaclyn M.; Walker, David A.

2017-01-01

In this commentary, we offer a set of visual tools that can assist education researchers, especially those in the field of mathematics, in developing cohesiveness from a mixed methods perspective, commencing at a study's research questions and literature review, through its data collection and analysis, and finally to its results. This expounds…

Correlational Analysis of Servant Leadership and School Climate

ERIC Educational Resources Information Center

Black, Glenda Lee

2010-01-01

The purpose of this mixed-method research study was to determine the extent that servant leadership was correlated with perceptions of school climate to identify whether there was a relationship between principals' and teachers' perceived practice of servant leadership and of school climate. The study employed a mixed-method approach by first…

Toward a Better Understanding of Student Perceptions of Writing Feedback: A Mixed Methods Study

ERIC Educational Resources Information Center

Zumbrunn, Sharon; Marrs, Sarah; Mewborn, Caitlin

2016-01-01

This explanatory sequential mixed methods study investigated the writing feedback perceptions of middle and high school students (N = 598). The predictive and mediational roles of writing self-efficacy and perceptions of writing feedback on student writing self-regulation aptitude were examined using mediation regression analysis. To augment the…

A Mixed-Methods Approach to Demotivating Factors among Iranian EFL Learners

ERIC Educational Resources Information Center

Ghonsooly, Behzad; Hassanzadeh, Tahereh; Samavarchi, Laila; Hamedi, Seyyedeh Mina

2017-01-01

This study used a mixed-methods approach to investigate Iranian EFL learners' attitudes towards demotivating factors which may hinder their success in a language learning course. In the quantitative phase, a sample of 337 undergraduate students from universities in Mashhad, Yazd and Gonabad completed a 34-item questionnaire. They also completed…

College Students; Justification for Digital Piracy: A Mixed Methods Study

ERIC Educational Resources Information Center

Yu, Szde

2012-01-01

A mixed methods project was devoted to understanding college students' justification for digital piracy. The project consisted of two studies, a qualitative one and a quantitative one. Qualitative interviews were conducted to identify main themes in students' justification for digital piracy, and then the findings were tested in a quantitative…

Developing a Spanish for Health Professions Course: A Preliminary Mixed-Methods Study

ERIC Educational Resources Information Center

Altstaedter, Laura Levi

2017-01-01

The mixed-methods pilot study described in this article traces the development of a Spanish for Specific Purposes: Health Professions course that was designed to help future health care professionals develop their linguistic proficiency and intercultural abilities. The study included nursing, medical, and dental students and was conducted at a…

Veteran Teacher Engagement in Site-Based Professional Development: A Mixed Methods Study

ERIC Educational Resources Information Center

Houston, Biaze L.

2016-01-01

This research study examined how teachers self-report their levels of engagement, which factors they believe contribute most to their engagement, and which assumptions of andragogy most heavily influence teacher engagement in site-based professional development. This study employed a convergent parallel mixed methods design to study veteran…

A new method for fingerprinting sediments source contributions using distances from discriminant function analysis

USDA-ARS?s Scientific Manuscript database

Mixing models have been used to predict sediment source contributions. The inherent problem of the mixing models limited the number of sediment sources. The objective of this study is to develop and evaluate a new method using Discriminant Function Analysis (DFA) to fingerprint sediment source contr...

Curiosity and Pedagogy: A Mixed-Methods Study of Student Experiences in the Design Studio

ERIC Educational Resources Information Center

Smith, Korydon H.

2010-01-01

Curiosity is often considered the foundation of learning. There is, however, little understanding of how (or if) pedagogy in higher education affects student curiosity, especially in the studio setting of architecture, interior design, and landscape architecture. This study used mixed-methods to investigate curiosity among design students in the…

Perceptions of Organizational Culture of a Multi-Campus Community College District: Mixed Methods in Concert

ERIC Educational Resources Information Center

Kuster Dale, Kimberly

2012-01-01

This concurrent, mixed-methods case study analyzed perceptions of current and preferred organizational culture within a rural, multi-campus community college district. This phenomenon was examined by analyzing and comparing data collected by surveying all full-time employees utilizing the Organizational Culture Assessment Instrument (OCAI) and…

Exploring Service Learning Outcomes in Students: A Mixed Methods Study for Nursing

ERIC Educational Resources Information Center

Martin, John F.

2017-01-01

This mixed methods study exploring student outcomes of service learning experiences is inter-disciplinary, near the intersection of higher education research, moral development, and nursing. The specific problem examined in this study is that service learning among university students is utilized by educators, but largely without a full…

Libraries in Online Elementary Schools: A Mixed-Methods Study

ERIC Educational Resources Information Center

Hibbard, Laura; Franklin, Teresa

2015-01-01

School libraries serve an important role; however, elementary students who attend schools online typically do not have a school library. This study followed an online school's inaugural year in instituting a library. A mixed methods approach examined data from focus groups, interviews, surveys, library-use records and oral reading fluency scores.…

Beginning Secondary Science Teacher Induction: A Two-Year Mixed Methods Study

ERIC Educational Resources Information Center

Luft, Julie A.; Firestone, Jonah B.; Wong, Sissy S.; Ortega, Ira; Adams, Krista; Bang, EunJin

2011-01-01

Those who study secondary science teachers are often concerned with preservice or in-service teacher development. Science teacher educators have acknowledged that this focus is limited, as the induction years of beginning teachers are an important component of teacher development. This mixed methods study focuses on the induction years of…

Factors, Practices, and Policies Influencing Students' Upward Transfer to Baccalaureate-Degree Programs and Institutions: A Mixed Methods Analysis

ERIC Educational Resources Information Center

LaSota, Robin Rae

2013-01-01

My dissertation utilizes an explanatory, sequential mixed-methods research design to assess factors influencing community college students' transfer probability to baccalaureate-granting institutions and to present promising practices in colleges and states directed at improving upward transfer, particularly for low-income and first-generation…

Perceived Barriers and Facilitators to School Social Work Practice: A Mixed-Methods Study

ERIC Educational Resources Information Center

Teasley, Martell; Canifield, James P.; Archuleta, Adrian J.; Crutchfield, Jandel; Chavis, Annie McCullough

2012-01-01

Understanding barriers to practice is a growing area within school social work research. Using a convenience sample of 284 school social workers, this study replicates the efforts of a mixed-method investigation designed to identify barriers and facilitators to school social work practice within different geographic locations. Time constraints and…

Caregiver Grief in Terminal Illness and Bereavement: A Mixed-Methods Study

ERIC Educational Resources Information Center

Waldrop, Deborah P.

2007-01-01

Caregivers experience multiple losses during the downhill trajectory of a loved one's terminal illness. Using mixed methods, this two-stage study explored caregiver grief during a terminal illness and after the care recipient's death. Caregiver grief was a state of heightened responsiveness during end-stage care: anxiety, hostility, depression,…

Technology-Enhanced Multimedia Instruction in Foreign Language Classrooms: A Mixed Methods Study

ERIC Educational Resources Information Center

Ketsman, Olha

2012-01-01

Technology-enhanced multimedia instruction in grades 6 through 12 foreign language classrooms was the focus of this study. The study's findings fill a gap in the literature through the report of how technology-enhanced multimedia instruction was successfully implemented in foreign language classrooms. Convergent parallel mixed methods study…

Mixed Methods Analysis of Multicultural Identity and Psychological Help Seeking Beliefs in College Students

ERIC Educational Resources Information Center

Walter, Jeffrey P.

2012-01-01

Research on the psychological help-seeking beliefs and behaviors of college students has provided evidence for differences among students based on demographic factors, with different variables being salient for different cultural groups. This mixed methods study focuses on understanding how common psychological help-seeking variables, including…

Mixed Methods Analysis of Counselor Views, Attitudes and Perceived Competencies Regarding the Treatment of Internet Pornography Addiction

ERIC Educational Resources Information Center

Hinman, Bradly K.

2013-01-01

The Internet offers unprecedented opportunity for individuals to have anonymous, inexpensive, and unrestricted access to an essentially unlimited range of sexually explicit materials. Counseling clients are increasingly presenting with problematic issues regarding Internet pornography use. The purposes of this mixed-method study were (a) to…

Creating Rich Portraits: A Mixed-Methods Approach to Understanding Profiles of Intrinsic and Extrinsic Motivations

ERIC Educational Resources Information Center

Corpus, Jennifer Henderlong; Wormington, Stephanie V.; Haimovitz, Kyla

2016-01-01

A person-centered, mixed-methods approach (self-report surveys, semistructured interviews, school records) was used to characterize and evaluate profiles of intrinsic and extrinsic motivations among 243 third- through eighth-grade students. Cluster analysis suggested four distinct profiles: high quantity (high intrinsic, high extrinsic), primarily…

Appreciative Accreditation: A Mixed Methods Explanatory Study of Appreciative Inquiry-Based Institutional Effectiveness Results in Higher Education

ERIC Educational Resources Information Center

Thibodeau, John

2011-01-01

This study examined the effects of using Appreciative Inquiry in accreditation and related institutional effectiveness activities within higher education. Using an explanatory participant-selection mixed methods approach, qualitative data from a series of interviews were used to explain the experiences of individuals identified from quantitative…

A Mixed Methods Study on Developing Low-Income Kindergarten Students' Intrinsic Reading Motivation

ERIC Educational Resources Information Center

Brady, Kara J.

2017-01-01

The purpose of this mixed methods study was to determine how the effects of kindergarten teachers' evidence-based literacy instructional practices impact the development of low-income kindergarten students' intrinsic reading motivation. The research questions are: (a) What are kindergarten teachers' perceptions of students' intrinsic reading…

Technology Adoption in Secondary Mathematics Teaching in Kenya: An Explanatory Mixed Methods Study

ERIC Educational Resources Information Center

Kamau, Leonard Mwathi

2014-01-01

This study examined the factors related to technology adoption by secondary mathematics teachers in Nyandarua and Nairobi counties in the Republic of Kenya. Using a sequential explanatory mixed methods approach, I collected qualitative data from interviews and classroom observations of six teachers to better understand statistical results from the…

A Cross-National Mixed-Method Study of Reality Pedagogy

ERIC Educational Resources Information Center

Sirrakos, George, Jr.; Fraser, Barry J.

2017-01-01

This mixed-methods cross-national study investigated the effectiveness of reality pedagogy (an approach in which teachers become part of students' activities, practices and rituals) in terms of changes in student perceptions of their learning environment and attitudes towards science. A questionnaire was administered to 142 students in grades 8-10…

First Generation College Student Leadership Potential: A Mixed Methods Analysis

ERIC Educational Resources Information Center

Hojan-Clark, Jane M.

2010-01-01

This mixed methods research compared the leadership potential of traditionally aged first generation college students to that of college students whose parents are college educated. A college education provides advantages to those who can obtain it (Baum & Payea, 2004; Black Issues in Higher Education, 2005; Education and the Value of…

Procrastination and Motivation of Undergraduates with Learning Disabilities: A Mixed-Methods Inquiry

ERIC Educational Resources Information Center

Klassen, Robert M.; Krawchuk, Lindsey L.; Lynch, Shane L.; Rajani, Sukaina

2008-01-01

The purpose of this mixed-methods article was to report two studies exploring the relationships between academic procrastination and motivation in 208 undergraduates with (n = 101) and without (n = 107) learning disabilities (LD). In Study 1, the results from self-report surveys found that individuals with LD reported significantly higher levels…

Exploring Dual Identification among Muslim-American Emerging Adults: A Mixed Methods Study

ERIC Educational Resources Information Center

Sirin, Selcuk R.; Bikmen, Nida; Mir, Madeeha; Fine, Michelle; Zaal, Mayida; Katsiaficas, Dalal

2008-01-01

This mixed methods study explored dual identification among Muslim-American emerging adults of immigrant origin. A closer look was taken at the relationship between American and Muslim identifications and how this relationship was influenced by experiences of discrimination, acculturative and religious practices, and whether it varied by gender.…

Mixed Methods in Indigenous Research: Building Relationships for Sustainable Intervention Outcomes

ERIC Educational Resources Information Center

Chilisa, Bagele; Tsheko, Gaelebale N.

2014-01-01

Indigenous communities raise concerns that they are overresearched and tired of research always asking the same questions and reproducing the same answers, thus pressuring researchers to open the discourse on mixed methods research so as to enable new debates and approaches to emerge. A postcolonial indigenous paradigm provides a theoretical…

Prevalence of Mixed Methods Research in Mathematics Education

ERIC Educational Resources Information Center

Ross, Amanda A.; Onwuegbuzie, Anthony J.

2012-01-01

In wake of federal legislation such as the No Child Left Behind Act of 2001 that have called for "scientifically based research in education," this study examined the possible trends in mixed methods research articles published in 2 peer-reviewed mathematics education journals (n = 87) from 2002 to 2006. The study also illustrates how…

Key Competencies and Characteristics for Innovative Teaching among Secondary School Teachers: A Mixed-Methods Research

ERIC Educational Resources Information Center

Zhu, Chang; Wang, Di

2014-01-01

This research aims to understand the key competencies and characteristics for innovative teaching as perceived by Chinese secondary teachers. A mixed-methods research was used to investigate secondary teachers' views. First, a qualitative study was conducted with interviews of teachers to understand the perceived key competencies and…

Toward a Unified Validation Framework in Mixed Methods Research

ERIC Educational Resources Information Center

Dellinger, Amy B.; Leech, Nancy L.

2007-01-01

The primary purpose of this article is to further discussions of validity in mixed methods research by introducing a validation framework to guide thinking about validity in this area. To justify the use of this framework, the authors discuss traditional terminology and validity criteria for quantitative and qualitative research, as well as…

Is Mixed Methods Research Used in Australian Career Development Research?

ERIC Educational Resources Information Center

Cameron, Roslyn

2010-01-01

Mixed methods research has become a substantive and growing methodological force that is growing in popularity within the human and social sciences. This article reports the findings of a study that has systematically reviewed articles from the "Australian Journal of Career Development" from 2004 to 2009. The aim of the study was to…