Assessing Children with the Wechsler Intelligence Scale for Children

Assessing Children with the Wechsler Intelligence Scale for Children - Third Edition

Professor comments:	Assessing Children with the Wechsler Intelligence Scale for Children - Third Edition
Good general description of the instrument to be reviewed.	The Wechsler Intelligence Scale for Children - Third Edition (WISC-III) is a revision of the WISC-R and made its appearance in 1991. Many years of research and revision have produced what Levinson and Folino (1994) claimed is the most "popular and [most] frequently used individually administered intelligence test" (p. 420). The test was developed to measure intelligence in children ages 6-0 to 16-11, and is based on existence of the g factor.
Good specific test info.	The WISC-III is comprised of two scales and allows computation for a variety of scores. The first scale, or Verbal Scale, has the subtests - Information, Similarities, Arithmetic, Vocabulary, Comprehension, and Digit Span (optional); and the second scale, or Performance Scale, has the subtests - Picture Completion, Coding, Picture Arrangement, Block Design, Object Assembly, Symbol Search (optional), and Mazes (optional). Scores are computed for individual subtest scores, the Verbal IQ score (VIQ), the Performance IQ score (PIQ), and the Full Scale IQ score (FSIQ). The individual subtest scores each have a mean of 10 and a standard deviation of 3 while the IQ scores have a mean of 100 and a standard deviation of 15. Four factor scores can also be calculated in the areas of Verbal Comprehension, Perceptual Organization, Freedom From Distractibility, and Processing Speed.
Excellent transition phrase	The Twelfth Mental Measurements Yearbook (1995) describes the test as "a 'measure of a child's intellectual ability'" (p. 1090), and through examination of research involving the WISC-III, I have found that a primary use of the test is assessment of children for placement into programs for the mentally retarded, the learning disabled, and the gifted. This paper will review the WISC-III and its use for categorizing children.
	Standardization The test was normed by using 2,200 children - 100 males and 100 females from 11 age groups extending from 6-0 to 16-11. They were highly representative of the 1988 U.S. Census and were stratified by geographic region, parental education, and race/ethnicity. Braden (1995), Sandoval (1995), Kaufman (1993), and Little (1992) have all described the standardization of the WISC-III as excellent.
Describe what was not specific	Reliability The test went through many revisions which took into consideration the suggestions of test users, the recommendations of experts, and information received through test pilots. The manual was written to give very specific instructions concerning the administration of the test in order to increase reliability; however, it is not specific enough in the area of interpretation (Little, 1992).
Why is this important? Interpret what these split-half test reliabilites mean.	According to Sandoval (1995), internal consistency appears at least as good, or better than, similar tests, and the inter-scorer reliabilities on Verbal subtests are greater than .92 due to examples, tables, and clear instructions provided in the manual. Even though the manual attempts to be detailed, some of the scoring remains subjective. (Interscorer reliabilities for the Performance subtests were not found). The Reliability Coefficients for the VIQ, PIQ, and FSIQ are .95, .91, and .96, respectively; and the Test-Retest Coefficients are .94, .87, and .94, also respectively (Levinson & Folino, 1994). The Split-Half Reliabilities are between .69 and .96 for all of the subtests with only two subtests showing coefficients below .75 (Kaufman, 1993).
Cite specific examples here.	There may be weaknesses due to the use of bonus points for performance speed. Kaufman (1993) explained that on the four subtests that use bonus points, 40% of the of the total possible points are bonus points awarded for speed; therefore, without these bonus points, a perfect score is often less than the national mean. Since the speed at which a child works can be affected by many nonintellectual factors such as the lack of sleep, illness, etc., the use of time bonuses may affect stability. Bonus points awarded for speed also inflate the split-half reliability coefficients for those subtests and caution should be used in interpretation. Regardless of these problems, research has shown that reliability is at least adequate or better on all subtest and IQ scores.
Initially list all that you will cover. This needs interpretation. Why is this important? More detail is necessary for factor analysis. This has not been previously discussed. Describe the 4 factors & why enough has not been done.	Validity Much research was conducted to verify predictive, concurrent, and construct validity. High correlations were found between the WISC-III and the Stanford-Binet Intelligence Scale: Fourth Edition (SB:FE) in studies by Lavin (1996) and by Carvajal, Hayes, Lackey, Rathke, Wiebe, and Weaver (1993). Vance and Fuller (1995) show high correlations between the WISC-III and the Wide Range Achievement Test - Third Edition (WRAT-3). As expected, the WISC-R, Otis-Lennon School Ability Test, and Differential Ability Scales all produce similar results to the WISC-III. High correlations were also found with other Wechsler scales; ability, achievement, and neuropsychological tests; and with school grades (Kaufman, 1993). Factor analysis supports the theory of a g factor; however, confusion arises over which and how many factors are actually being measured. Not enough research has been done to find out how helpful or valid the four factor analysis is pertaining to the assessment and placement of children with special needs.
More information could be included.	Bias A great effort was made to eliminate item bias from the WISC-III. Many experts reviewed the items, pointing out those which could cause a problem. Some minority groups were over sampled for the purpose of locating and eliminating biased items. However, the question still remains regarding test fairness concerning the verbal subtests for certain populations (Little, 1992; Post & Mitchell, 1993). Some desire to see additional scales added to the WISC-III that will more adequately assess special groups of children (Post & Mitchell, 1993; Kaufman, 1993).
Good summary.	Conclusion Although the standardization, the reliability, and the validity are all impressive, caution should always be taken when using the WISC-III to assess and classify a child. As with any test, error has not been totally eliminated and results may be misleading if used alone. The WISC-III does not have detailed instructions for interpretation, leaving openings for discrepancies. It is important to remember that labels have a tendency to stick with a child, and self-esteem, for this age group especially, relies heavily on the opinions of others. Since both the emotional, as well as the educational needs of the child need to be met, using the WISC-III as a tool for assessment and placement into a special program is acceptable if used along with an assortment of other evaluation materials. In doing so, children will be less likely to be improperly diagnosed and labeled.
P -- Capital	References Braden, J. P. (1995). Review of the Wechsler Intelligence Scale for Children, Third Edition. The Twelfth Mental Measurements Yearbook. Lincoln, Nebraska: University of Nebraska Press. Carvajal, H. H., Hayes, J. E., Lackey, K. L., Rathke, M. L., Wiebe, D. A., & Weaver, K. A. (1993). Correlations between scores on the Wechsler Intelligence Scale for Children-III and the General Purpose Abbreviated Battery of the Stanford-Binet IV. Psychological Reports, 72, 1167-1170. Kaufman, A. S. (1993). King WISC the third assumes the throne. Journal of School Psychology, 31, 345-354. Lavin, C. (1996). The Wechsler Intelligence Scale for Children-Third Edition and the Stanford-Binet Intelligence Scale: Fourth Edition: a preliminary study of validity. Psychological Reports, 78, 491-496. Levinson, E. M., & Folino, L. (1994). Correlations of scores on the Gifted Evaluation Scale with those on WISC-III and Kaufman Brief Intelligence Test for students referred for gifted evaluation. Psychological Reports, 74, 419-424. Little, S. G. (1992). The WISC-III: everything old is new again. School Psychology Quarterly, 7, 136-142. Post, K. R., & Mitchell, H. R. (1993). The WISC-III: a reality check. Journal of psychology, 31, 541-545. Sandoval, J. (1995). Review of the Wechsler Intelligence Scale for Children, Third Edition. The Twelfth Mental Measurements Yearbook. Lincoln, Nebraska: University of Nebraska Press. Vance, B. & Fuller, G. B. (1995). Relation of scores on WISC-III and WRAT-3 for a sample of referred children and youth. Psychological Reports, 76, 371-374.