Two- and four-subtest short forms of the WAIS--R: Validity in a psychiatric sample.

Abstract

The validity of two-and four-subtest short forms of the Wechsler Adult Intelligence Scale -Revised (WAIS-R) was investigated using a sample of 45 male and 45 female psychiatric patients. Both short forms were highly correlated with Full Scale IQ, although there was a mean IQ overestimate. Forty-two percent of the subjects were placed in different IQ categories by SF2, whereas a 40% misclassification rate occurred with SF4. SF2 and SF4 estimates were within the 95% confidence limits of Full Scale IQ for 62% and 72% of the subjects, respectively. Shortened administration time reduced the accuracy of SF2, but did not influence SF4 IQ estimates. SF4 validity was better for females than for males.A number of recent investigations have examined short forms of the Wechsler Adult Intelligence Scale -Revised (WAIS-R; Wechsler, 1981). Judging by the number of publications, short forms which eliminate subtests are somewhat more popular than those which retain all of the subtests but eliminate items (Adams, Smigielski, & Jenkins, 1984;Dinning & Kraft, 1983;Satz & Mogel, 1962;Silverstein, 1982b). Silverstein (1982a) has provided tables for estimating Full Scale IQs (FSIQ) for a two-subtest short form consisting of Vocabulary and Block Design (SF2) and a four-subtest short form consisting of Vocabulary, Arithmetic, Block Design, and Picture Arrangement (SF4). Using data from the WAIS-R test manual, Silverstein's criteria for the selection of these short forms was primarily validity (i.e., those combinations of subtests having the highest correlations with FSIQ). Although SF4 was not the most valid tetrad of subtests, it nevertheless possessed high validity (r = .93) and had a history of clinical use with the WISC-R (Kaufman, 1976) and the WA1S (Doppelt, 1956;Silverstein, 1985). Cyr and Brooker (1984) have also addressed the selection of WAIS-R short forms. Using Wechsler's (1981) data, these authors averaged validity and reliability coefficients to arrive at the best short form combinations. Cyr and Brooker corroborate the Vocabulary-Block Design combination as the best dyad, although their best tetrad consisted of Vocabulary, Block Design, Arithmetic, and Similarities.Portions of this paper were presented at the Canadian Psychological Association's forty-sixth annual convention,

Intellectual Decline in Schizophrenia: Evidence from a Prospective Birth Cohort 28 Year Follow-up Study

“…It is of interest that the estimated adult IQ level of this community sample of patients with schizophrenia was 91.2. While the IQ estimate used in this investigation (using the Vocabulary and Block Design subtests, Brooker & Cyr, 1986) is known to overestimate Full Scale IQ by about three points (Margolis, Taylor, & Greenlief, 1986;Roth, Hughes, Monkowski & Crosson, 1984;Ryan, Larsen, & Prifitera, 1983;Thompson, Howard, & Anderson, 1986), it is very close to the average IQ level of approximately 90 reported by Aylward, Walker, and Bettes (1984) in their meta-analysis, and in the average IQ derived from our seven previous studies of neuropsychological functioning in schizophrenia . The results from this combination of clinical, twin (Goldberg et al, 1995), and community samples suggests that the average IQ of approximately 90 is a good estimate of the population mean of persons with chronic schizophrenia.…”

Evaluation of Kaufman's short forms of the WAIS-R with psychiatric inpatients

“…For example, Vocabulary requires the use of a relatively subjective scoring system, while some Picture Arrangement and Block Design items may take up to 2 minutes to administer. In addition, WAIS-R administration time estimates show that this short form may take from 30 to 43 minutes to administer (Ryan & Rosenberg, 1984;Thompson, 1987;Thompson, Howard, & Anderson, 1986;Ward, Selby, & Clark, 1987). In the interest of providing a reliable and valid Full Scale IQ estimate in the briefest amount of time possible, Kaufman (Kaufman, 1990;Kaufman & Ishikuma, 1989) developed three WAIS-R subtest-reduction short forms, which consist of two (SF2), three (SF3), and four (SF4) subtests.…”

“…An attractive feature of SF3 is its ability to assess each of the three factors that consistently appear in the WAIS-R factor-analytic literature; i.e., Verbal Comprehension, Freedom from Distractability, and Perceptual Organization. As with SF2, SF3 is quick to administer, easy to score, and addresses motivational and attentional considerations (Kaufman, 1990;Kaufman & Ishikuma, 1989;Thompson, 1987;Thompson et al, 1986). SF4 is made up of Arithmetic, Similarities, Picture Completion, and Digit Symbol and takes approximately 19 minutes to administer.…”

Comparison of three WISC-III short forms: Weighing psychometric, clinical, and practical factors

“…Yet in contrast to the average administration time of 36 min for $ilverst@in's short form (Ryan & Rosenberg, 1984;Thompson, Howard, &Anderson, 1986;Ward et a]., 1987), the S-A-PC-D$Y tetrad requires about 19 rnin to give (Grossman et &I., 1993;Kaufman et al, 1991).…”