Beaulieu et al. (2007) make a great comment about the difficulty with case studies: they ask how a case study can “be used to inspire other work, without implicitly or explicitly falling into a universalizing fallacy? (p. 673). As they go on to explain, case studies tend to either be seen as unable to generate theory or as attempting to explain all experiences with one experiment (through what Yin calls “cross-case analysis,” p. 58). Yin (1981) argues that cross-case analysis, or generating theory across multiple case studies, is possible through constructing theories for each case and seeing if, allowing for some flexibility, they can correspond to theories for other cases.
Interestingly, Yin goes on to say that this method is not less scientific than similar methods used for scientific experiments. I agree with Yin – of course cross-case analysis may lead to over-generalization, but that is always a risk for research of any kind. Furthermore, as Luker points out a number of times in her book, theory-generating is an important task of case studies. Without the hypotheses about broader theories that case studies put forward, there would be no opportunity to test those theories against a broader range of cases and therefore generating strong new theoretical explanations would be much more difficult.
Beaulieu, A., Scharnhorst, A. and Wouters, P. (2007). Not another case study: A middle-range interrogation of ethnographic case studies in the exploration of e-science. Science, Technology and Human Values, 32.6, 672-692.
Yin, R.K. (1981). The case study crisis: Some answers. Administrative Science Quarterly, 26(1), 58-65.