Case Studies and Theory Development in the Social Sciences - Alexander L. George [124]
Such differentiated theories not only allow for more discriminating explanations; they are also of greater practical value for policymakers, who can use them to make more discriminating diagnoses of emerging situations. Contrast, for example, a general explanatory theory such as “war is often the result of miscalculation” with a typological theory that distinguishes the conditions under which different types of miscalculations—misapprehensions about the changing balance of power, misinterpretations of an adversary’s motives, failure to understand the bureaucratic or domestic constraints on the adversary, and so on—may lead to war. As another example, policymakers who are aware of different types of surprise may be better able to avoid being surprised by an adversary.
From Typologies to Typological Theories
The relationships among types, typologies, typological theories, and their usefulness in case study methods for theory development are important but underdeveloped topics. Some researchers have noted that typologies can control for specified variables and help establish similar cases for purposes of comparison.470 Others have downplayed the role of typologies, without distinguishing them clearly from typological theories. We argue that typologies and especially typological theories can serve more ambitious purposes in case study research and social sciences than is generally acknowledged.
The formulation of typologies is a familiar activity in social science research. Analysts often partition events into types that share specified combinations of factors.471 Ideally, these types are mutually exclusive and exhaustive—that is, every case of the phenomenon fits into a type, and only into one type, and types are designed to minimize within-type variation and maximize variation between types.472 Investigators are often interested in making a complex phenomenon, such as revolutions or military interventions, more manageable by dividing it into variants or types. They do so by identifying clusters of characteristics that differentiate instances of the phenomenon. Depending on the investigator’s research objectives, identification of a single type may suffice, or the investigator may need to develop a differentiated typology of many types.
Typologies may thus take many different forms and have different uses, some more ambitious than others. Among the less ambitious uses, a typology may do little more than identify the qualitative types of a single multidimensional dependent or independent variable. For example, a differentiated dependent variable could be types of deterrence failure, and a differentiated independent variable could be types of coercive diplomacy employed to change the behavior of an adversary. Typologies can also characterize variants of a given phenomenon in terms of conjunctions of variables, such as types of social unrest that may or may not lead to revolutions. In their most complex form, typologies can include conjunctions of multidimensional independent variables together with types of a multidimensional dependent variable. For example, a typology might include types of military interventions that vary by regional context, domestic politics in the target state, scale, scope, goals, and instruments employed.473
In a typology, in contrast to a typological theory, the constituent characteristics or combinations of factors are not necessarily theoretical variables. This is likely to be the case when the typology has not been developed within a theoretical framework. Nor does a typology itself link independent and dependent variables in a causal