Wechsler Intelligence Scale for Children--Revised

Purpose: Designed as a comprehensive measure of cognitive ability for children.

Population: Ages 6-16.

Score: Verbal, Performance, and Full Scale Scores.

Time: (50-75) minutes.

Author: David Wechsler.

Publisher: The Psychological Corporation.

Description: The Wechsler Intelligence Scale for Children-Revised (WISC-R) is a general test of intelligence, which Wechsler defined as, "... the global capacity of the individual to act purposefully, to think rationally, and to deal effectively with his environment." In keeping with this definition of intelligence as an aggregate of mental aptitudes or abilities, the WISC consists of 13 subtests divided into two parts, verbal and performance.

Scoring: The WISC-R is a collection of 13 distinct subtest divided into two scales - a Verbal Scale and a Performance Scale. The six Verbal Scale tests use language-based items, whereas the seven Performance Scales use visual-motor items that are less dependent on language. Five of the subtest in each scale produce scale-specific IQS, and the 10 subtest scores produce a Full Scale IQ.

Reliability: Each of the three IQ scales has an internal consistency reliability coefficient of .89 or above in the standardization group over the entire age range covered by the scale. Average internal consistency reliability coefficients, based on the 11 age groups, are .96 for the Full Scale IQ, .94 for the Verbal Scale IQ, and .90 for the Performance Scale IQ. The average subtest reliability coefficients range from a low of .70 for Object Assembly to a high of .86 for Vocabulary. The average reliability coefficients range from .77 to .86 (Mdn = .80) for the Verbal Scale subtests and from .70 to .85 (Mdn = .72) for the Performance Scale subtests. Test-retest stability coefficients were .95 for the Full Scale IQ, .93 for the Verbal Scale IQ, and .90 for the Performance Scale IQ.

Validity: Because the WISC-R overlaps with the WPPSI in the age range of 6-0-0 to 6-7-15, either of the two tests can be used to evaluate children in this age range. The correlations were .80 for the Verbal Scales, .80 for the Performance Scales, and .82 for the Full Scales. In a study in which 5 to 6-year-old middle-class children were administered both tests, with a one-year test-retest interval, the WISC-R yielded IQS that were 5 points lower on the average than those of the WPPSI. Correlations between the two tests were .81 for the Verbal Scales, .80 for the Performance Scales, and .94 for the Full Scales. Four studies comparing the WISC-R and the Stanford-Binet: Fourth Edition are reported in the Technical Manual of the Fourth Edition. Correlations ranged from .66 to .83 between the WISC-R Full Scale IQ and the Fourth Edition composite.

Norms: The WISC-R was standardized on a sample of 2,200 American children selected as representative of the population on the basis of the 1970 U.S. Census.

Suggested Uses: It is suggested that the WISC-R is an appropriate instrument for practitioners and clinical researchers in assessing children’s intelligence.