In this guide, Dawn Flanagan, Kevin McGrew, and Samuel Ortiz modernize the interpretation of the Wechsler Intelligence Scales by applying Gf-Gc theory and the cross-battery approach to intellectual assessment and interpretation. They show you in-depth how to use cross-battery principles and techniques to augment the Wechsler Intelligence Scales (WPPSI-R, WISC-III, WAIS-III) in a psychometrically defensible manner and how to interpret the results of Wechsler-based cross-battery assessments within the context of today's theory and research. In the three comprehensive parts, the guide shows the approach used by the authors: a comprehensive review of the psychometric, theoretical, and qualitative characteristics of all of the individual subtests of the WPPSI-R, WISC-III, WAIS-III, WMS-III, and CMS; and a thorough understanding of the product of grounding cognitive ability assessment and interpretation, with the Wechsler Scales, in strong theory and research -- the Wechsler-based Gf-Gc cross-battery approach. What's more, The Wechsler-based cross-battery approach presented here narrows the theory-practice gap in the field of intellectual assessment and includes well-articulated theory and research based guidelines for conducting Wechsler cross-battery assessments with culturally and linguistically diverse individuals.