Wechsler-based CHC cross-battery assessment and reading achievement: Strengthening the validity of interpretations drawn from Wechsler test scores

The Cattell-Hom-Carroll (CHC) cross-battery approach to assessing cognitive abilities has been introduced to the field recently as an alternative to t raditional assessment instruments and techniques (Flanagan, McGrew, & Ortiz , 2000; McGrew & Flanagan, 1998). This theory-based method of assessment wa s developed to provide a more valid and defensible way of deriving meaning from test scores than that provided by the traditional (and largely atheore tical) Wechsler Scale approach. The present study is the first to investiga te the validity of the cross-battery approach using a sample of elementary school children (N= 166) who were administered the Wechsler Intelligence Sc ale for Children-Revised (WISC-R; Wechsler, 1974) and Woodcock-Johnson Psyc he-Educational Battery-Revised (WJ-R; Woodcock & Johnson, 1989). Structural Equation Modeling was used to examine whether (a) Wechsler-based CHC cross -battery assessment explained more variance in reading achievement than a t raditional Wechsler model, and (b) whether the Wechsler-based CHC cross-bat tery model provided a more accurate description of the general and specific abilities on general and specific reading achievement than the traditional Wechsler model, as predicted in the extant g/specific abilities literature . Findings showed that the g factor underlying the Wechsler-based CHC cross -battery model accounted for substantially more variance in reading achieve ment (25%) than the g factor underlying the atheoretical Verbal Comprehensi on-Perceptual Organization-Freedom From Distractibility (VC-PO-FFD) Wechsle r model. In addition, findings demonstrated that when assessments are organ ized around the strong CHC theoretical model, specific cognitive abilities, including auditory processing (Ga), crystallized intelligence (Gc), and pr ocessing speed (Gs) explained a significant portion of variance in reading achievement beyond that accounted for by g. These findings suggest that a W echsler-based CHC cross-battery approach is an effective way of ensuring va lid representation of multiple cognitive abilities, specifically those that have been found to affect significantly the development of reading skills.