Regardless of one's field of interest within sociology (or social anthropology or social psychology), studies which explicitly and systematically compare data from two or more societies can make distinctive contributions to theory. Four of these contributions are: (1) tobroadenthe range of variation in variables, thereby requiring theory to explain more than it has heretofore; (2) toreplicatestudies done in one society in other, similar societies; (3) togeneralizepropositions from one type of society to other types of societies; and (4) tospecifyapparently discrepant findings from different societies by developing new propositions which account for the originally discrepant findings. A number of comparative studies, drawn from the several hundred published since 1950, and distributed through a wide variety of sub-fields of sociology, are codified in terms of these four kinds of contributions that comparative analysis can make to sociological theory.