Short-forms of the UK WAIS-R: regression equations and their predictive validity in a general population sample

A sample of 200 healthy subjects, representative of the adult UK population in terms of age, sex and social class distribution, were administered a full-length WAIS-R (UK). Regression equations were built to predict full-length IQ from a series of short-forms. The short-forms ranged from a two-subtest version proposed by Silverstein (1982) to a seven-subtest version proposed by Warrington, James & Maciejewski (1986). Regression equations, their standard errors of estimate and confidence intervals are presented as well as IQ conversion tables. The short-forms are evaluated in terms of their validity in predicting full-length IQ and in terms of their clinical utility. The advantages of regression-based estimates of full-length IQ over those derived from conventional prorating are discussed.