Case Studies and Theory Development in the Social Sciences - Alexander L. George [42]
• Theory testing case studies assess the validity and scope conditions of single or competing theories. As discussed in Chapter 6, it is important in tests of theories to identify whether the test cases are most-likely, least-likely, or crucial for one or more theories. Testing may also be devised to identify the scope conditions of theories (the conditions under which they are most- and least-likely to apply).
• Plausibility probes are preliminary studies on relatively untested theories and hypotheses to determine whether more intensive and laborious testing is warranted. The term “plausibility probe” should not be used too loosely, as it is not intended to lower the standards of evidence and inference and allow for easy tests on most-likely cases.
• “Building Block” studies of particular types or subtypes of a phenomenon identify common patterns or serve a particular kind of heuristic purpose. These studies can be component parts of larger contingent generalizations and typological theories. Some methodologists have criticized single-case studies and studies of cases that do not vary in their dependent variable.162 However, we argue that single-case studies and “no variance” studies of multiple cases can be useful if they pose “tough tests” for theories or identify alternative causal paths to similar outcomes when equifinality is present.163 (See also the more detailed discussion of “building blocks” theory below.)
Researchers should clearly identify which of these six types of theory-building is being undertaken in a given study; readers should not be left to find an answer to this question on their own. The researcher may fail to make it clear, for example, whether the study is an effort at theory testing or merely a plausibility probe. Or the researcher may fail to indicate whether and what kind of “tough test” of the theory is supposedly being conducted.164
These six research objectives vary in their uses of induction and deduction. Also, a single research design may be able to accomplish more than one purpose—such as heuristic and theory testing goals—as long as it is careful in using evidence and making inferences in ways appropriate to each research objective. For example, while it is not legitimate to derive a theory from a set of data and then claim to test it on the same data, it is sometimes possible to test a theory on different data, or new or previously unobserved facts, from the same case.165
Specific questions that need to be addressed in designating the research objectives include:
• What is the phenomenon or type of behavior that is being singled out for examination; that is, what is the class or subclass of events of which the cases will be instances?
• Is the phenomenon to be explained thought to be an empirical universal (i.e., no variation in the dependent variable), so that the research problem is to account for the lack of variation in the outcomes of the cases? Or is the goal to explain an observable variation in the dependent variable?
• What theoretical framework will be employed? Is there an existing theory or rival candidate theories that bear on those aspects of the phenomenon or behavior that are to be explained? If not, what provisional theory or theories will the researcher formulate for the purpose of the study? If provisional theories are lacking, what theory-relevant variables will be considered?
• Which aspects of the existing theory or theories will be singled out for testing, refinement, or elaboration?
• If the research objective is to assess the causal effects or the predictions of a particular theory (or independent variable), is that theory sufficiently specified