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Reliability of score differences on Wechsler's intelligence scales
1University of California, Los Angeles.
Abstract:
Comparisons are made between the results given by two formulae for the reliability of the difference between an individual subtest score and the average subtest score on a scale to which that subtest belongs. For the WAIS-R and the WISC-R, the correct reliabilities reported here are appreciably higher than the incorrect reliabilities reported previously, and the apparent reversal of this result for the WPPSI is explained as an artifact. Even the correct reliabilities are very low, however, more than three-quarters of them below .70.
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