Single-Outcome Studies

Most methodological work on case studies understands this topic as a study of a case where the objective is to discover something about a broader population of cases. Yet, many case studies (so-called) do not assume this nomothetic goal; their aim is to investigate a bounded unit in an attempt to elucidate a single outcome occurring within that unit. This is referred to as a single-outcome study to distinguish it from the usual genre of case study. In this article, the author discusses the utility of single-outcome studies and the different types of argumentation and causal logic that they embrace. The author proceeds to discuss the methodological components of the single-outcome study, which is understood according to three analytic angles: nested analysis (large- N cross-case analysis), most-similar analysis (small- N cross-case analysis) and within-case analysis (evidence drawn from the case of special interest). The article concludes with a discussion of a common difficulty encountered by single-outcome analysis, that is, reconciling cross-case and within-case evidence, both of which purport to explain the single outcome of interest.