A confirmatory analysis of the factor structure and cross-age invariance of the Wechsler Adult Intelligence Scale-Third Edition.

In the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III; D. Wechsler, 1997), the manual reports several confirmatory factor analyses in support of the instrument's latent factor structure. In practice, examiners frequently compare an examinee's score from a current administration of the WAIS-III with the results from a previous test administration. Implicit in test-retest score comparisons is evidence that scores retain similar interpretive meaning across time. Establishing an instrument's factorial invariance provides the foundation for this practice. This study investigated the factorial invariance of the WAIS-III across the instrument's 13 age groups. The overall results from this study generally support both configural and factorial invariance of the WAIS-III when the 11 primary tests are administered.