Psychology in rhe Schools 1981, / 8 , 147-148

UTILITY OF CODING VS. MAZES SUBTESTS IN EVALUATING GIFTEDNESS WITH THE WISC-R

DAN WRIGHT AND JAMES D. HEATER

Ralston Public Schools

A recommendation that Mazes be substituted for Coding in the assessment of giftedness with the WISC-R was investigated by including both subtests in the evalua- tion of 50 children referred for verification of eligibility. Scaled scores on Mazes were significantly higher than those on Coding for the group, although the proportion of children meeting the established criterion was similar under inclusion of either subtest in the computation of Full Scale Scores. These data offer general support for the selective inclusion of Mazes in this type of assessment.

Regulations by most state departments of education on the identification of gifted children specify rigid IQ cutoffs. Since there is no room for consideration of interpretive factors such as the standard error of measurement, every legitimate advantage should be given to the subject of such an evaluation. Kaufman (1979) suggests substituting the Mazes subtest for Coding when using the WISC-R, since it is more of a cognitive task and correlates more highly with Full Scale IQ. Children whose true abilities lie near some arbitrarily high cutoff should stand a better chance of meeting the criterion if their scores are not regressed toward the mean by the inclusion of a subtest that is poorly related to the abilities in question. Though apparently logical, there are no data to sup- port the recommendation; the present study seeks to determine if there is an empirically demonstrable advantage.

METHOD Subjects

Subjects were 50 elementary students nominated by regular classroom teachers for possible inclusion in their district’s program for gifted students. Students were nominated because of superior academic achievement, and all within the same calendar year. There were 34 males and 16 females, with an age range of 6-0 to 12-3 and a mean age of 9-2. All students were white, of middle-class origin, and from the same small, ur- ban school district in the Midwest. Procedure

Each student was administered 1 1 WISC-R subtests, including all 6 Performance subtests, by certified school psychologists. Means and standard deviations were com- puted on scaled scores for Coding and Mazes, and a correlated t-test was performed to test the difference of these scores for the group. Full Scale Scores were computed twice, first including Coding and then including Mazes. Full Scale Scores were examined on a case by case basis to determine the proportion of children meeting or exceeding the 98th percentile (FSIQ 2131) with either Coding or Mazes included in the computation.

RESULTS A N D DISCUSSION Means and standard deviations of Scaled Scores for Coding and Mazes were 1 1.16

and 2.40, and 12.66 and 2.70, respectively. Although a paired t-test of correlated means

Requests for reprints should be sent to Dan Wright, Ralston Public Schools, 8545 Park Drive, Ralston, N E 68127.

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148 Psychology in the Schools, April, 1981, Vol. 18, No. 2.

revealed a significant difference in the expected direction between scores on Coding and Mazes (p<.05, one-tailed), the magnitude of the difference was nearly obscured in its effect on mean Full Scale Scores under the two conditions. The difference between Coding and Mazes scores within individual cases ranged from a 7-point advantage for Mazes to a 4-point advantage for Coding. The magnitude of Full Scale Scores likewise displayed considerable variation within cases, depending on which of the subtests was in- cluded in the computation.

The variation of Full Scale Scores according to choice of subtest also affected the comparison of each case against the previously established criterion for program eligibility. The majority of cases either met or failed the criterion under both conditions; however, a very few cases met the criterion with the inclusion of one subtest or the other, but not under both conditions. Of the three cases thus involved, two met the criterion with the inclusion of Mazes only and one with the inclusion of Coding only.

The significant mean difference between the two subtests, which amounted to one- half the standard deviation of the Scaled Score distribution, justifies the inclusion of Mazes over Coding for this type of assessment. Decision making was not much affected by choice of subtest in the present sample, because the mean ability level (mean FSIQ= 124.4, SD=9.5 with Mazes included) was considerably below the cutoff. Prac- titioners following Kaufman’s recommendation should not expect a dramatic change in the proportion of referred students who are verified. For samples of children with a mean ability level nearer the cutoff, more children will be affected by subtest selection. It is also possible that separate analyses by sex, or comparing Coding A with Coding B, might lend stronger support for Kaufman’s recommendation with certain groups of referred youngsters.

REFERENCE K A u I M ~ N , A. S. Intelligent testing with the WISC-R. New York: Wiley, 1979.