Validity of the WISC-III for deaf and hard of hearing persons.

The relationships of the WISC-III Performance scale with the WISC-R Performance scale and the WRAT-R subscales were investigated for a sample of 47 students who are deaf and hard of hearing. Over a three year time period, the relationships between the WISC-III and WISC-R Performance IQs was high, r(43) = +.93. As anticipated, the WISC-III and WISC-R Performance IQ. A Varimax rotation revealed the presence of two factors, Perceptual Organization and Processing Speed, which accounted for 76.5% of the variance in the WISC-III performance IQ. Of the six WISC-III Performance subtests, only Coding did not contribute to the Performance IQ. Students who communicated via Total Communication (M = 92.5) exhibited higher Performance IQ means than did students who communicated orally (M = 82.6). The WISC-III Performance IQ was moderately related to the WRAT-R subscales, having the strongest association with the Arithmetic subscale. Implications of these findings for practitioners are discussed.