Construct Validity of the AAMR Adaptive Behavior Scale-School: 2

Abstract

The AAMR Adaptive Behavior Scale-School: 2 (ABS-S: 2; Lambert, Nihira, & Leland, 1993) is the second revision of the original 1975 AAMD Adaptive Behavior Scale, Public School Version (ABS-PSV). Although the ABS-S: 2 is a significant improvement over the first revision of the instrument, Adaptive Behavior Scale, School Edition (ABS-SE) there is a need for further study of the scale's construct validity. This study examined the construct validity of the ABS-S: 2 through exploratory factor analyses. Estimates of subtest specificity also were calculated to provide users with an empirical basis for interpreting the ABS-S: 2's domains as separate adaptive behavior strengths and weaknesses. Results indicated that the ABS-S: 2 is best understood as a two-factor instrument for both children with mental retardation (MR) and for those without mental retardation (Non-MR). The test does seem to reflect personal independence and social behavior as the scale's authors intended. Because the data strongly indicate a 2-factor model for both the MR and Non-MR samples, users should be cautious when interpreting ABS-S: 2 results in terms of the 5-factor model presented by the test's authors. The estimates of unique variance derived also indicate that most of the ABS-S: 2 domains do not have sufficient subtest specificity to be interpreted as unique adaptive behavior strengths or weaknesses.