Drawing on the work of the Survey Research Center of the University of Michigan on party identification and the Likert approach to attitude measurement, this paper develops a procedure for measuring the concept of social identity. Suggestions are made for using the procedure to analyze the behavior of respondents and to understand the groups that are the objects of identification. The paper closes with the suggestion that further factor analyses be done to determine whether there are general social identities that are present across all samples of respondents or whether the clustering of social identities is particular to each sample of respondents.