Case Studies and Theory Development in the Social Sciences - Alexander L. George [43]
Researchers’ initial efforts to formulate research objectives for a study often lack sufficient clarity or are too ambitious. Unless these defects are corrected, the study will lack a clear focus, and it will probably not be possible to design a study to achieve the objectives.
Better results are achieved if the “class” of the phenomenon to be investigated is not defined too broadly. Most successful studies, in fact, have worked with a well-defined, smaller-scope subclass of the general phenomenon.166 Case study researchers often move down the “ladder of generality” to contingent generalizations and the identification of more circumscribed scope conditions of a theory, rather than up toward broader but less precise generalizations.167
Working with a specified subclass of a general phenomenon is also an effective strategy for theory development. Instead of trying in one study to develop a general theory for an entire phenomenon (e.g., all “military interventions”), the investigator should think instead of formulating a typology of different kinds of interventions and proceed to choose one type or subclass of interventions for study, such as “protracted interventions.” Or the study may focus on interventions by various policy instruments, interventions on behalf of different goals, or interventions in the context of different alliance structures or balances of power. The result of any single circumscribed study will be one part of an overall theory of intervention. Other studies, focusing on different types or subclasses of intervention, will be needed to contribute to the formulation of a general theory of interventions, if that is the broader, more ambitious research program. If the typology of interventions identifies six major kinds of intervention that are deemed to be of theoretical and practical interest, each subtype can be regarded as a candidate for separate study and each study will investigate instances of that subtype.
This approach to theory development is a “building block” procedure. Each block—a study of each subtype—fills a “space” in the overall theory or in a typological theory. In addition, the component provided by each building block is itself a contribution to theory; though its scope is limited, it addresses the important problem or puzzle associated with the type of intervention that led to the selection and formulation of the research objective. Its generalizations are more narrow and contingent than those of the general “covering laws” variety that some hold up as the ideal, but they are also more precise and may involve relations with higher probabilities.168 In other words, the building block developed for a subtype is self sufficient; its validity and usefulness do not depend upon the existence of other studies of different subclasses of that general phenomenon.
If an investigator wishes to compare and contrast two or more different types of intervention, the study must be guided by clearly defined puzzles, questions, or problems that may be different from or similar to those of a study of a single subclass. For example, the objective may be to discover under what conditions (and through what paths) Outcome X occurs, and under what conditions (and through what paths) Outcome Y occurs. Alternatively, the objective may be to examine under what conditions Policy A leads to Outcome Y and under what other conditions Policy A leads to Outcome X. Similarly, the focus may be on explaining the outcome of a case or a subclass or type of cases, or it may be on explaining the causal role of a particular independent variable across cases.
Task Two: Developing a Research Strategy: Specification of Variables
In the course of formulating a research objective for the study—which may change during the study—the investigator also develops a research strategy