Case Studies and Theory Development in the Social Sciences - Alexander L. George [47]
Task Four: Describing the Variance in Variables
The way in which variance is described is critical to the usefulness of case analyses in furthering the development of new theories or the assessment or refinement of existing theories. This point needs emphasis because it is often overlooked in designing studies—particularly statistical studies of a large-N. The researcher’s decision about how to describe variance is important for achieving research objectives because the discovery of potential causal relationships may depend on how the variance in these variables is postulated. Basing this decision on a priori judgments may be risky and unproductive; the investigator is more likely to develop sensitive ways of describing variance in the variables after he or she has become familiar with how they vary in the historical cases examined. An it-erative procedure for determining how best to describe variance is therefore recommended.178
The variance may in some instances be best described in terms of qualitative types of outcomes. In others, it may be best described in terms of quantitative measures. In either case, one important question is how many categories to establish for the variables. Fewer categories—such as dichotomous variables—are good for parsimony but may lack richness and nuance, while greater numbers of categories gain richness but sacrifice parsimony. The trade-off between parsimony and extreme richness should be determined by considering the purposes of each individual study.
In a study of deterrence, for example, Alexander George and Richard Smoke found it to be inadequate and unproductive to define deterrence outcomes simply as “successes” or “failures.”179 Instead, their explanations of individual cases of failure enabled them to identify different types of failures. This led to a typology of failures, with each type of failure having a different explanation. This typology allowed George and Smoke to see that deterrence failures exemplified the phenomenon of equifinality. The result was a more discriminating and policy-relevant explanatory theory for deterrence failures.180
The differentiation of types can apply to the characterization of independent as well as dependent variables. In attempting to identify conditions associated with the success or failure of efforts to employ a strategy of coercive diplomacy, one set of investigators identified important variants of that strategy.181 In their study, coercive diplomacy was treated as an independent variable. From an analysis of different cases, four types of the coercive diplomacy strategy were identified: the explicit ultimatum, the tacit ultimatum, the “gradual turning of the screw,” and the “try and see” variant. By differentiating the independent variable in this way, it was possible to develop a more discriminating analysis of the effectiveness of coercive diplomacy and to identify some of the factors that favored or handicapped the success of each variant. A very general or undifferentiated depiction of the independent variable would have “washed out” the fact that variants of coercive diplomacy may have different impacts on outcomes, or it might have resulted in ambiguous or invalid results. In addition, the identification of different variants of coercive diplomacy strategy has important implications for the selection of cases.
Task Five: Formulation of Data Requirements and General Questions
The case study method will be more effective if the research design includes a specification of the data to be obtained from the case or cases under study. Data requirements should be determined by the theoretical framework and the research strategy to be used for achieving the study’s research objectives.