title: Two investigations of the validity of the WISC-III.
abstract: Two studies were conducted in which the validity of the WISC-III was investigated. In Study 1, WISC-R and WISC-III IQs were correlated for a sample of 53 students, who, although originally meeting criteria for a disability category through use of the WISC-R, did not meet eligibility criteria upon reevaluation with the WISC-III. Corrected correlations between IQs were high, ranging from .80 to .87, and were comparable to figures reported in the WISC-III manual. Consistent with the WISC-III manual, WISC-III IQs were 8, 5, and 7 points lower than the WISC-R Full Scale, Verbal, and Performance IQs, respectively. In Study 2, the criterion validity of the WISC-III with the WRAT-R Reading, Spelling, and Arithmetic subscales and with the PPVT-R was investigated for a sample of 32 students with mental retardation. The WISC-III IQs and PPVT-R scores were highly correlated, sharing between 64 to 76% of variance. Correlations between WISC-III IQs and scores on the WRAT-R Reading and Arithmetic subscales were moderate. Surprisingly, the WISC-III IQs were not related to the WRAT-R Spelling scores. Implications of both studies for assessment specialists are discussed.
authors.affiliation: Department of Counselor Education and Psychology, Arkansas State University, State University 72467-0940, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Slate
mesh_terms: D000293:Adolescent; D001131:Arkansas; D002648:Child; D004519:Education, Special; D004608:Eligibility Determination; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis* / Q000523:psychology; D007360:Intelligence; D007859:Learning Disabilities / Q000175:diagnosis* / Q000523:psychology; D008297:Male; D011594:Psychometrics; D014888:Wechsler Scales / Q000706:statistics & numerical data*