There are a variety of definitions for what mixed methods studies mean and this page will introduce several such definitions to highlight some of the confusion that exists around mixed methods terminology, but also to identify similar views of what mixed method research means.
The quantitative / qualitative divide has been long debated among social science researchers and recent development in research methodology advocates for a more integrated approach to the investigation of social phenomena. Although for many years researchers have reported studies in which both quantitative and qualitative methods were employed, it is only in the recent years that the interest into formal mixed methods or multimethodology has increased.
But the area of mixed methods is as debated as the research methods themselves and this is mainly because academics and researchers have different understandings of what is meant by mixed methods research and what are the main types of mixed method designs. A brief introduction into what is meant by mixed methods research and some suggested definitions can be found below. These are definitions proposed by some of the better known authors in mixed methods research and they represent different understandings of what is involved in designing, conducting or reviewing mixed methods studies.
Mixed method research, or multimethodology, uses quantitative and qualitative methods in a single or multiphased study (Tashakkori & Teddlie, 1998) at all or many research stages (Creswell, 1995) including sampling strategies, data collection & analysis, findings synthesis, and integration & reporting. The data collected, analysed and synthesized can be numerical, but also textual / visual / multimedia data.
As Johnston et al. (2007) point out, the definitions proposed by the leaders in the field of mixed metholds research have varying levels of specificity, the majority suggesting that what is mixed is the quantitative and qualitative research, while some also includes historical research in addition to the two paradigms already mentioned. Other authors refer to 'within' research paradigm mixing. Some definitions mention when or at what stage of research the mixing takes place. Here are some examples of such definitions:
Tashakkori and Creswell, for example, take in consideration how mixed methods can be found at different research stages:
"Research in which the investigator collects and analyses data, integrates the findings, and draws inferences using both qualitative and quantitative approaches or methods in a single study or programme of inquiry." (Tashakkori and Creswell, 2007, p.4)
Jennifer Greene explores the overall purposes of using mixed method research in her definition:
"Mixed method inquiry is an approach to investigating the social world that ideally involves more than one methodological tradition and thus more than one way of knowing, along with more than one kind of technique for gathering, analyzing, and representing human pheomena, all for the purpose of better understanding". (in Johnston et al., 2007)
Pat Bazeley touches on the distinction between mixed methods and multimethod:
"I tend to distinguish between mixed methods and multimethod, although if I need a generic term, I used mixed methods. Multimethod research is when different approaches or methods are used in parallel or sequence but are not integrated until inferences are being made. Mixed methods research involves the use of more than one approach to or method of design, data collection or data analysis within a single program of study, with integration of the different approaches or methods occurring during the program of study, and not just at its concluding point. Note that I am not limiting this to a combination of qualitative and quantiative research only, but more broadly, combination of any different approaches/methods/analyses." (in Johnston et al., 2007)
Al Hunter has a different understanding of multimethod research in which mixing also includes 'within' research paradigm mixing (e.g. QUAL + QUAL):
"Mixed methods is a terms that is usually used to designate combining quantitative and qualitative research methods in the same research project. I prefer the term multimethod research to indicate that different sytles of research may be combined in the same research project. These need not be restricted to quantitative and qualitative; but may include, for example, qualitative participant observation with qualitative in-depth interviewing. Alternatively it could include quantitative survey research with quantitative experimental research. And of course it would include quantitative with qualitative styles". (in Johnston et al., 2007).
Tashakkori, A. & Teddlie, C. (1998). Mixed Methodology: Combining qualitative and quantitative approaches. Thousands Oaks, CA: Sage.
Creswell, J. W. (1995). Research design: Qualitative and quantitative approaches. Thousand Oaks, CA: Sage.
Maxwell, J.A. and Loomis, D. M. (2003). Mixed methods design: An alternative approach in Handbook of Mixed Methods in Social & Behavioral Research, ed. Abbas Tashakkori and Teddlie Charles, London: Sage, pp. 241-271.
R. Burke Johnson, Anthony J. Onwuegbuzie, and Lisa A. Turner (2007). Toward a Definition of Mixed Methods Research, Journal of Mixed Methods Research, vol. 1: pp. 112 - 133.
Tashakkori, A. and Creswell, JW. (2007). Exploring the nature of research questions in mixed methods research. Journal of Mixed Methods Research, 1: 207-211.