Estimating Full Scale IQ While Minimizing the Effects of Practice

The present study attempted to ascertain the best estimate of true Wechsler Adult Intelligence Scale-Revised (WAIS-R) Full Scale IQ (FSIQ) when confronted with an individual who recently had been administered the WAIS-R. Sixty-five college undergraduate participants were administered the WAIS-R twice within 14 days. WAIS-R summary scores, factor scores, and short-form estimates obtained from the second assessment were compared to FSIQ at the first evaluation. The results indicated that Verbal IQ, the Verbal Comprehension factor score, and subtracting 6 points from the current FSIQ are the least affected by repeat assessment and the most accurate estimates of FSIQ at the first evaluation. Use of these estimates of FSIQ are encouraged when evaluating an individual who has been administered the WAIS-R in the recent past.