An Introduction to the Wechsler Intelligence Tests

This special issue focuses on two lead articles examining the factor structure of the fourth editions of the Wechsler Adult Intelligence Scales (WAIS-IV; Wechsler, 2003) and the Wechsler Intelligence Scales for Children (WISC-IV; Wechsler, 2008). These articles are followed by 9 commentaries and a final response by the authors of the lead articles. These diverse approaches critically assess the theoretical and practice implications of the structure of intelligence measured by the Wechsler scales.

Technical and Practical Issues in the Structure and Clinical Invariance of the Wechsler Scales

This discussion article addresses issues related to expansion of the Wechsler model from four to five factors; multiple broad CHC abilities measured by the Arithmetic subtest; advantages and disadvantages of including complex tasks requiring integration of multiple broad abilities when measuring intelligence; limitations of factor analysis, which constrain test developers to creating specific broad and narrow abilities as opposed to integrative tasks; implications from brain imaging research showing the critical role of neurological pathways that integrate brain regions; close relationship of the fluid reasoning factor to g, and the inadequacies of factor analytically driven statistical definitions of g in the development of improved models of intelligence. In this rejoinder to the commentaries in this special issue on structural models of the WAIS-IV and WISC-IV, the advantages and disadvantages of Schmid–Leiman’s transformation, which removes the effects of g on the broad abilities, and the use of nested or bifactor models in evaluating models of intelligence are also discussed.