Indices of Qualitative Variation and Political Measurement

ETHODOLOGICAL and technical solutions to problems posed in a discipline such as political science are often overlooked or independently discovered and rediscovered. This is due, in part, to the necessarily primary emphasis of the political scientist on substantive problems. As a consequence, however, researchers working on apparently disparate conceptual and theoretical issues may not recognize the possibility that a single technical procedure may be common to their concerns. The search for an appropriate technique is thus often inefficiently pursued in a variety of contexts. The intent of this essay is to short-circuit this problem in one specific area by creating awareness of a statistical device that can be of benefit in a number of important political science applications. All standard statisics texts discuss the measurement of variation in a univariate