| Abstract: | Indices of item diffculty and item discrimination were analyzed for the items comprising the Wechsler Intelligence Scale for Children - Revised as obtained from a group of 142 subjects with Full Scale IQs below 96. Item validities were estimated by computing the biserial correlation between dichotomized item responses and the total weight score. Kendall's tau was computed for each item. The item difficulties for each subtest except Information and Vocabulary are roughly in the same rank order as those obtained by the stadardization group. Evidence from the study indicates that the increase in the number of items on the WISC-R helped to increase its internal Validity. Analysis of the data ragarding the internal consistency of the test indicates that the majority of the items operate as significant discriminators. Changes in the order of that administration and /or revision of the record form would not seem warranted on the basis of the present study. |
