Although personality research has made much progress in developing an individual-difference psychology of creativity, the nature of this phenomenon can only be fully illuminated if a social psychology of creativity is developed as well. Yet experimental studies of social and environmental influences on creativity are extremely rare. A major obstacle to such research is the criterion problem: the lack of a clear operational definition and an appropriate assessment methodology. For a variety of reasons, both the popular creativity tests and the subjective assessment techniques used in some previous creativity studies are ill-suited to social psychological studies of creativity. A consensual definition of creativity is presented and, as a refinement of previous subjective methods, a reliable subjective assessment technique based on that definition is described. Several studies testing the methodology in both artistic and verbal domains are presented, and the advantages and limitations of this technique are discussed. The present methodology can be particularly useful for the development of a social psychology of creativity because of the nature of the tasks employed and the nature of the creativity assessments obtained. In the discussion, creativity assessment is considered as one instance illustrating the more general issue of the divergent aims and methods of personality psychology and social psychology.