Abstract
The utility of Wechsler's intelligence scales, along with some important limitations, is deeply rooted in some basic theoretical notions about the tests. The present article traces the theoretical basis for the Wechsler scales and examines empirical evidence for and against the theory. Consistent with Wechsler's theoretical notions, construct and predictive validity of the Wechsler Scales are greatest at the more global IQ level and weakest at the level of profile analysis and individual subtest interpretation. Implications for clinical practice are discussed.