Psychometric and Geometric Characteristics of the Revised Interpersonal Adjective Scales (IAS-R).

Previous research has suggested that the Interpersonal Adjective Scales (IAS) have properties that are compatible with the substantive, structural, and external characteristics required by the circumplex-based interpersonal theory which guided scale construction procedures. In the present study, we describe an item-analytic procedure that identifies and selects items in terms of their estimated geometric location within a circumplex model and we apply the procedure to the task of reducing the 128-item IAS to a 64-item short form version (IAS-R). Scales constructed to conform to a circumplex model are evaluated by somewhat different structural criteria than are those developed to conform to other multivariate models and these differences are illustrated. The resultant IAS-R was found to have improved substantive and structural characteristics and acceptable reliability. We discuss possible applications of this highly efficient measure of interpersonal behavior.