Case Studies and Theory Development in the Social Sciences - Alexander L. George [14]
There is potential for confusion among the terms “comparative methods,” “case study methods,” and “qualitative methods.” In one view, the comparative method (the use of comparisons among a small number of cases) is distinct from the case study method, which in this view involves the internal examination of single cases. However, we define case study methods to include both within-case analysis of single cases and comparisons of a small number of cases, since there is a growing consensus that the strongest means of drawing inferences from case studies is the use of a combination of within-case analysis and cross-case comparisons within a single study or research program (although single-case studies can also play a role in theory development). The term “qualitative methods” is sometimes used to encompass both case studies carried out with a relatively positivist view of the philosophy of science and those implemented with a postmodern or interpretive view. We exclude postmodern narratives from our view of case studies, though some of the more disciplined forms of discourse analysis approach our view of case studies. This book therefore hews to the traditional terminology in focusing on case studies as the subset of qualitative methods that aspires to cumulative and progressive generalizations about social life and seeks to develop and apply clear standards for judging whether some generalizations fit the social world better than others.
Strengths of Case Study Methods
Case studies are generally strong precisely where statistical methods and formal models are weak. We identify four strong advantages of case methods that make them valuable in testing hypotheses and particularly useful for theory development: their potential for achieving high conceptual validity; their strong procedures for fostering new hypotheses; their value as a useful means to closely examine the hypothesized role of causal mechanisms in the context of individual cases; and their capacity for addressing causal complexity.
CONCEPTUAL VALIDITY
Case studies allow a researcher to achieve high levels of conceptual validity, or to identify and measure the indicators that best represent the theoretical concepts the researcher intends to measure. Many of the variables that interest social scientists, such as democracy, power, political culture, state strength, and so on are notoriously difficult to measure. For example, a procedure that is “democratic” in one cultural context might be profoundly undemocratic in another. Thus, researchers must carry out “contextualized comparison,” which “self-consciously seeks to address the issue of equivalence by searching for analytically equivalent phenomena—even if expressed in substantively different terms—across different contexts.”41 This requires a detailed consideration of contextual factors, which is extremely difficult to do in statistical studies but is common in case studies.
Whereas statistical studies run the risk of “conceptual stretching” by lumping together dissimilar cases to get a larger sample, case studies allow for conceptual refinements with a higher level of validity over a smaller number of cases. Research in comparative politics on democratic systems, for example, has proceeded in part through the conceptual development of “democracy with adjectives,” where each adjective, such as a “federal,” “parliamentary,” “presidential,” or “authoritarian” democracy, denotes a subtype or subclass with a smaller number of cases that are presumably more similar than those under the overall concept of “democracy.” 42 A common path of theoretical development has been from broad generalizations,