Normative Factor Structure of the AAMR Adaptive Behavior Scale-School, Second Edition

Abstract

The Adaptive Behavior Scale-School, Second Edition (ABS-S:2; Lambert, Nihira, & Leland, 1993) is one of the most popular tests of adaptive behavior. Critical methodological flaws in the confirmatory factor analysis reported in the test manual and the results of independent exploratory factor analyses leave the structural validity of the ABS-S:2 underdefined. The present study conducted exploratory factor analysis of the combined ABS-S:2 normative sample of 3,328 students (2,074 with mental retardation and 1,254 without mental retardation). Following principal axis factor extraction and oblique rotation, a two-factor solution was deemed the best dimensional model. These results suggest that interpretation of the ABS-S:2 should focus on its two major conceptual components (personal independence and social behavior) rather than the five factors and 16 domains endorsed by its authors.