Qualitative Comparative Analysis
Wendy Olsen, CCSR/Social Statistics
Qualitative Comparative Analysis (QCA) offers a new, systematic way of studying configurations of cases. QCA is used in comparative research and when using case-study research methods. The QCA analysts interprets the data qualitatively whilst also looking at causality between the variables. Thus the two-stage approach to studying causality has a qualitative first stage and a systematic second stage using QCA. QCA is truly a mixed-methods approach to research. The basic data-handling mechanism is a simple qualitative table of data. This matrix is made up of rows and columns. Its column elements can be binary (yes/no), ordinal, or scaled index variates. QCA is best suited to small- to medium-N case-study projects with between 3 and 250 cases. Crisp-set QCA uses only binary variates for its truth table. Fuzzy-set QCA also uses ordinal variates. A variate is a column of numbers representing real, not hypothetical, cases. In implementing QCA, one can code up the case-study data using NVIVO 7 software to create substantive case attributes. Multiple-level nested or non-nested cases can be handled. Fuzzy-set analysis is an optional extra stage, which also uses Boolean logic, but which is not necessary for QCA and tends not to be as qualitative as crisp-set QCA (csQCA) itself.
Experts at Manchester
Wendy Olsen, Senior Lecturer in Social Science Research Methods (SED) and in Socio-Economic Research (SOSS)
Matthias Vom Hau, Brooks World Poverty Institute
A research grant from the British Academy allowed Manchester University to host an Expert Roundtable on the Study of Strategies of Social Change using the Method of Qualitative Comparative Analysis (QCA) in 2008. Experts from Manchester University and the UK then visited Japan to hold a second roundtable there in 2009. A mixed-methods research training workshop took place on 15 June, 2010.
• Rihoux, B., & Ragin, C. C. (2009). Configurational comparative methods. Qualitative Comparative Analysis (QCA) and related techniques (Applied Social Research Methods). Thousand Oaks and London: Sage.
• Rihoux, B., and M. Grimm, eds. (2006). Innovative Comparative Methods For Policy Analysis: Beyond the quantitative-qualitative divide. New York, NY, Springer.
• Ragin, C.C. (2008). Redesigning social inquiry: Set relations in social research. Chicago: Chicago University Press.
• Ragin, C. C. (2000). Fuzzy-set social science. Chicago; London, University of Chicago Press. (One only needs to read the first half to cover QCA; the second half covers Fuzzy Set Analysis.)
• Byrne, D., and C. Ragin, eds. (2009), Handbook of Case-Centred Research Methods, London: Sage.
Join the JISC email list about QCA: QUAL-COMPARE
Wendy Olsen offers software support and advice via both these web sites.
What is...? talk recording
Methods Fair 2012 - talk on QCA by Steph Thomson, CCSR