The direct product model is a new analysis tool for modeling multitrait-multimethod data. This model may avoid some of the problems associated with conventional analysis of multitrait-multimethod data by allowing for the possibility of multiplicative traitmethod interactions. Based on the work of Browne (1984; 1990), we suggest several refinements in testing this model, including use of confirmatory procedures for testing model fit and implementation of a hierarchical approach to model comparisons. We provide an illustration of the refined direct product approach using a study of three types of organizational citizenship behavior. The results supply evidence for convergent and discriminant validity of the three constructs, and suggest that job incumbents, supervisors, and peers have significantly different perspectives of organizational citizenship behavior.