A comparison of the Shipley vs. WAIS-R subtests in predicting WAIS-R Full Scale IQ

The Shipley and WAIS-R were administered to a diverse psychiatric and neurologic sample of 186 males. Estimates of Full Scale WAIS-R IQ obtained from the Shipley regression equation of Zachary, Crumpton, and Spiegel (1985) yielded a correlation of .73 with WAIS-R IQ, considerably lower than the .85 and .87 reported by the authors. Development of a new regression equation with more variables did not yield a significantly higher correlation. Several individual subtests or pairs of subtests provided equal or better estimates of WAIS-R IQ within the same population and required less administration time. The Shipley is recommended as an adequate IQ estimate when individual testing is not feasible.