The importance of the interpersonal circle in organizing the interpersonal domain is complemented by its empirical relations with broader personality taxonomies and with more specific personality variables. Yet circumplex structure in interpersonal measures has often been investigated using the "eyeball test" rather than using circumplex criteria of known effectiveness. Simulations (Acton, 1999) showed the effectiveness of 5 exploratory criteria (3 entirely new) that assess the properties of equal spacing, constant radius, and no preferred rotation. Along with Browne's (1992) criterion, these were applied to the Interpersonal Checklist (ICL; LaForge & Suczek, 1955, N = 763), Interpersonal Adjective Scales (IAS; Wiggins, 1979; Ns = 716 and 187), Revised IAS (IAS-R; Wiggins, Trapnell, Phillips, 1988; N = 474), Inventory of Interpersonal Problems Circumplex Scales (IIP-C; Alden, Wiggins, Pincus, 1990; Ns = 616 and 1,381), and Inventory of Interpersonal Goals (IIG; Horowitz, Dryer, & Krasnoperova, 1997; N = 318). In corroboration of interpersonal theory, all showed circumplex structure.