Second-order confirmatory factor analysis of the WAIS-III

According to Vernon's structure-of-intellect paradigm, abilities can be conceptualized as a hierarchy, with a factor of general intelligence at the top of the hierarchy, and successively more specific abilities toward the bottom. This paradigm has proven useful for interpreting a number of Wechsler intelligence scales. However, most of the research with this paradigm has used exploratory factor analysis, and the validity of the paradigm for the newest Wechsler Adult Intelligence Scale (WAIS-III) has yet to be evaluated. The present study examined the WAIS-III using second-order confirmatory factor analysis, which is a more appropriate analytic tool when specific hypotheses are tested. Using the standardization sample for the WAIS-III (N = 2,450), support was found for the hierarchical factor structure with a second-order factor of general intelligence and four first-order factors of Verbal Comprehension, Perceptual Organization, Working Memory, and Processing Speed.