Investigating Group Differences

Frequently, sociologists encounter research problems which call for assessing the extent to which two or more categories of people or events can be maximally distinguished from one another with respect to a number of common variable attributes. Unfortunately, predictive models which evidently accomplish just this, in addition to providing rules for the classification of new entities, have been conspicuously absent from the literature. Discriminant analysis, a multivariate technique extensively employed in physical anthropology, clinical psychology, and the biological sciences, has made scant headway in sociology, even though many of our most interesting substantive investigations are clearly amenable to it. The purpose of this paper, then, is first to suggest numerous research situations in which two-group and multiple discriminant analyses might be productively applied. By way of illustration, a brief example of the use of discriminant analysis for data on student politics will be presented. Second, the principal methodological problems attributed to discriminant analysis will be summarized and possible solutions suggested.