Intrasubject Differences in the Wechsler Intelligence Scale for Children-Revised

Abstract

The three different types of standard error of measurement are discussed and tables of appropriate values are reported. These values may be used in setting confidence boundaries around test scores, assessing changes accrued across time as the result of retest, and assessing intrasubject versus intratest scale score differences in order to determine relative strengths and weaknesses. Two important considerations may be reached by comparing two sets of values. First, the use of the values contained in this article will result in more accurate decisions than would use of the values reported in the Wechsler Intelligence Scale for Children-Revised (WISC-R). Second, the WISC-R was found to be a slightly more precise measurement technique than was reported in its manual. Additionally, the reliability of verbal versus performance differences was computed, as was the percentage of the normative sample that exhibited reliable differences.