Abstract

External validity is typically regarded as the downside of case study research by methodologists and social scientists; case studies, however, are often aimed at drawing lessons that are generalizable to new contexts. The gap between the generalizability potential of case studies and the research goals demands closer scrutiny. I suggest that the conclusion that case study research is weak in external validity follows from a set of assumptions that I term the "traditional view," which are disputable at best. In this view, external validity is treated as a matter of mere representativeness. I argue that it is best understood instead as a problem of inference and that the emphasis should be placed on the comparability of the study rather than on the typicality of the case. By making case studies highly comparable, their external validity can be reliably and efficiently assessed and, in this way, their generalizability potential enhanced