A Confirmatory Analysis of the Wechsler Adult Intelligence Scale-Third Edition: Is the Verbal/Performance Discrepancy Justified? - Practical Assessment, Research & Evaluation

Now, in its third revision, the Wechsler Adult Intelligence Scale-III has a new factor structure. The theoretical structure of the new instrument is hierarchical in nature and contains four firstorder factors with a second-order g factor at the apex. In addition to the theoretical hierarchical factor structure of the new instrument, there is an implied factor structure that is used for scoring. This implied structure contains a Full Scale IQ Index, Verbal IQ Index, and a Performance IQ Index. This study investigated the construct validity of both the implied and explicit theoretical structure of the instrument. The results indicate the WAIS-III provides an excellent measure of the four factor model and a general factor. The data, however, did not support the construct validity of a Verbal IQ Index/Performance IQ Index dichotomy. These findings and practical implications for the clinician using the instrument are discussed.