MYTH OF THE MASTER DETECTIVE - RELIABILITY OF INTERPRETATIONS FOR KAUFMAN INTELLIGENT TESTING APPROACH TO THE WISC-III

Based on the internal-consistency and test-retest reliability coeffici ents reported for the Wechsler Intelligence Scale for Children-Third E dition (WISC-III), computer simulation methods were used to examine th e reliability of interpretations for Kaufman's ''intelligent testing'' approach to the WISC-III. Two independent samples of 5,000 cases were generated for each of three sources of variability in scores: content sampling, time sampling, and the combined or additive effect of conte nt and time sampling. Because many additional sources of error were no t represented by the model (scoring errors, practice effects), the sim ulation provided a ''best case'' scenario for the evaluation of Kaufma n's system. Analyses of decision reliability showed that VIQ-PIQ diffe rences, factor index-score differences, and ipsative profile patterns on the WISC-III could not be interpreted with confidence. Consequently , Kaufman's assertion that the limitations of IQ testing can be overco me through skilled ''detective work'' may be Viewed as mythology. Impl ications for ''intelligent'' professional practice and public policy i n the assessment of children are discussed.