An investigation of Kaufman's method for determining scatter on the WISC-R

Abstract

Kaufman's procedures (Journal of Learning Disabilities, 9, 160-168, 1976) for determining intersubtest scatter on the WISC-R were investigated by means of J. M. Sattler's revised tables (Assessment of children's intelligence and special abilities (2nd ed.), Boston, Allyn and Bacon, 1982) for determining significant subtest fluctuations. Data from the standardization sample were analyzed and new normative tables for interpreting subtest scatter were produced. The results indicated that Sattler's revised tables yielded more conservative estimates of subtest scatter than those originally reported by Kaufman. McNemar chi squares indicated that, in almost every instance, a significant number of subtests switched from being significantly discrepant by Kaufman's ±3 criterion to nonsignificant by Sattler's revised values. It was concluded that Kaufman's ±3 rule of thumb is no longer defensible on any reasonable statistical grounds and that the clinician should utilize Sattler's revised table of critical values when determining whether a subtest deviates significantly from the mean Verbal or Performance scaled score. The normative tables generated in the present study should be consulted when assessing whether the overall amount of scatter observed in a particular child's profile represents "unusual" scatter. © 1986.