Qualitative comparative analysis

Wendy Olsen, CCSR/Social Statistics.

Video: Wendy Olsen

Qualitative comparative analysis by Wendy Olsen

Video: Wendy Olsen

What is qualitative comparative analysis? by Wendy Olsen

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.

Venn Diagram produced by the 'visualizer' tool
Figure 3.2 Venn diagram corresponding to Table 3.4 (4 conditions)*
* Venn diagram produced by the 'visualiser' tool, TOSMANA 1.3.0.0 software.

Experts at Manchester

  • Dr Wendy Olsen, Senior Lecturer in Social Science Research Methods (SED) and in Socio-Economic Research (SOSS)
  • Matthias Vom Hau, Brooks World Poverty Institute (now joined with the Institute for Development Policy and Management to become the Global Development 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.

Key references

  • 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.

Web links

Wendy Olsen offers software support and advice via both these web sites.

Staff interested in qualitative software Nvivo

  • Dr. Rudolf Sinkovics - Alliance Manchester Business School (AMBS), International Business
  • Dr. Yanuar Nugroho - formerly Alliance Manchester Business School (AMBS), Technological innovation
  • Prof Cathy Cassell - formerly Alliance Manchester Business School (AMBS), Qualitative methods in organisational research
  • Dr. Richard Kyle - Nursing, Midwifery and Social Work, Health and social geographer
  • Dr. Sarah Kendal - Nursing, Midwifery and Social Work, Emotional wellbeing interventions
  • Dr. Ziv Amir - Nursing, Midwifery and Social Work, Survivorship and cancer
  • Dr Linda McGowan - Nursing, Midwifery and Social Work, Women's health  
  • Prof. Alys Young - Nursing, Midwifery and Social Work, Social work research
  • Wendy Olsen - School of Social Sciences, Sociology of economic life
  • Prof. Jennifer Mason - Social Sciences, Kinship and family

Staff interested in qualitative software Atlas-TI

  • Dr. Yanuar Nugroho - formerly Alliance Manchester Business School (AMBS), Technological innovation
  • Dr. Jane Griffiths - Nursing, Midwifery and Social Work, Supportive and Palliative Care in Community Nursing
  • Dr. Malcolm Campbell - Nursing, Midwifery and Social Work, Statistics
  • Dr. Richard Kyle - Nursing, Midwifery and Social Work, Health and social geographer
  • Prof. Christi Deaton - Nursing, Midwifery and Social Work, Structural equation modelling and multi-level modelling
  • Prof. Peter Callery - Nursing, Midwifery and Social Work, Self care of long term conditions in childhood and young people

PDF slides

Download PDF slides of the presentation 'What is QCA?'