Estimating WAIS-R IQ from the Shipley Institute of Living Scale: a Replication

Zachary, Crumpton, and Spiegel (1985) introduced a linear regression and continuous norming procedure for estimating Full Scale WAIS-R IQ from the Shipley Institute of Living Scale. The present study replicated their method with 55 adult psychiatric inpatients and day hospital patients. A high correlation (r = .85), an extremely small mean difference in IQ (.8 points), and an acceptable average absolute difference (7.6 points) were found between estimated and obtained WAIS-R. Sines and Simmons tables (1959) for Shipley estimates of WAIS IQ produced a high correlation (r = .86), but large mean and average absolute differences (13.1 and 13.6 points, respectively). The study supports use of the Zachary et al. procedure for estimating WAIS-R IQ from Shipley scores in a psychiatric population.