Examination of the structural, convergent, and incremental validity of the Reynolds Intellectual Assessment Scales (RIAS) with a clinical sample.

Abstract

Empirical examination of the Reynolds Intellectual Assessment Scales (RIAS; C. R. Reynolds & R. W. Kamphaus, 2003a) has produced mixed results regarding its internal structure and convergent validity. Various aspects of validity of RIAS scores with a sample (N = 521) of adolescents and adults seeking psychological evaluations at a university-based clinic were examined. Results from exploratory factor analysis indicated only 1 factor, and confirmatory factor analysis (CFA) indicated that the 1-factor model was a good fit and a better fit than the 2-factor model. Hierarchical factor analysis indicated the higher order, general intelligence factor accounted for the largest amount of variance. Correlations with other measures of verbal/crystallized and nonverbal/fluid intelligence were supportive of the convergent validity of the Verbal Intelligence Index but not the Nonverbal Intelligence Index. Joint CFA with these additional measures resulted in a superior fit of the 2-factor model compared with the 1-factor model, although the Odd-Item-Out subtest was found to be a poor measure of nonverbal/fluid intelligence. Incremental validity analyses indicated that the Composite Intelligence Index explained a medium to large portion of academic achievement variance; the NIX and VIX explained a small amount of remaining variance. Implications regarding interpretation of the RIAS when assessing similar individuals are discussed.