A SPLIT IN THE VERBAL COMPREHENSION FACTOR IN WAIS AND WISC-R PROFILES

SHANNA MCGEE AND COKE BROWN Idaho State University

Examined the pattern of verbal subscale scores on the WAIS and WISC-R given to college students and elementary students who were being considered for a gifted and talented program, respectively, in Idaho and found a sub- stantial number of students whose scores were highly discrepant from ex- pected patterns. For 51 of 129 college students, the scores on the Com- prehension subscale differed significantly (p <.05) from both the Informa- tion (1) and Vocabulary (V) subscale scores. When this group of students was compared to the rest of those tested, C scores were significantly higher (p <.Ol), V scores were significantly lower (p <.05), and I scores tended to be lower. The WISC-R scores for the two samples of the elementary students (Ns = 164, 219) suggested that the triangle pattern (C significantly higher than both V and I) begins to appear at the fourth-grade level. These results are puzzling because Comprehension scores significantly higher than those on Information and Vocabulary usually are expected from persons with good native intellectual endowment, but limited educational and cultural opportunities. Data from other parts of the country are needed.

In factor-analytic studies of the WAIS and WISC-R (cf. Bannatyne, 1971, 1974; Cohen, 1957, 1959; Davis, 1959; Kaufman, 1975, 1979; Newland & Smith, 1967), scores on the Comprehension, Vocabulary, and Information subtests normally correlate highly (.70 - .85) with one another and cluster together to form a verbal comprehension factor. However, in testing done in Pocatello, Idaho, from 1976 through 1980, there were a large number of cases in which the verbal comprehension factor appeared to split, with C scaled scores significantly higher than V and I scaled scores. This pattern, which was found in three different samples of Ss, is referred to as “triangle scores.”

METHOD Subjects and Procedure

Data from three samples of test respondents were included in the analyses. Sample 1 included I29 students in introductory psychology courses at Idaho State University (mean age 22.5), who were given extra credit for participation. All but 7 of these students had received their primary and secondary education in Idaho. Sample 2 was made up of 164 local elementary students, grades 1-6, who were being considered for a program for gifted and talented children. Sample 3 included test results for all students ( N = 129) tested for this program in the local school district in 1978. Sample 3 included 25 children who also were included in Sample 2. The college sample was administered the WAIS and the elementary samples the WISC-R.

RESULTS AND DISCUSSION Data analysis of the test records of our first sample (129 college students) revealed

that correlations between subtest scores diverged from the norm. The correlation (.75) of I with V fell in the range cited above for other studies and is similar to that cited by Wechsler (1958) (31). However, the correlations of C with I and V (.41 and .51, respec- tively) are well below those normally found and those cited by Wechsler (.70 and .73, respectively.)

Next, a subsample of 49 respondents whose C subscale scores were significantly higher than both their I and V subscale scores was identified (plus two individuals whose

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582 Journal of Clinical Psychology, March, 1984, Vol. 40, No . 2

C scores were significantly lower). This identification was based on the findings of Newland and Smith (1967), which indicate that a 3-point difference between C and I scaled scores is significant at the .05 level, and a difference between C and V scaled scores of three points is also significant at the .05 level.

This subsample, referred to as “triangle scores,” then was compared to the rest of the college sample. When the subsample means were compared on the three subscales, the triangle group had significantly higher C scores (t(127) = 7.9, p <.01) and significantly lower V scores (t(127) = 2.1, p <.05), but, although their I scores were lower, they were not significantly so. Furthermore, there was not a significant difference in verbal IQs between the two groups (t(127) = 1.0, p <.05); means of 114.4 and 112.9 were found for triangles and non-triangles, respectively.

When the correlations between subscales were computed separately for the triangle scores and the remaining (normal) scores, it was readily apparent that the depressed cor- relations of C with V and I for the entire group were due to the influence of the triangle scores. Subscale intercorrelations for the normal group approximated those generally reported in the literature (Wechsler, 1958, pp. 69-80). Correlations of the triangle data that compared C with I and V (see Table 1) were significantly lower (2 = 2.64, p <.01 and Z = 2.90, p <.01, respectively) than those in the normal group. The correlations between triangle subscale scores and verbal IQs were also consistently lower. The difference in correlations, however, was significant only for the C vs. verbal IQ cor- relations (Z = 2.14, p <.05).

The data for sample 2, the WISC-R records of 164 local elementary school children who were being considered for a gifted and talented program, using the Newland and Smith cut-offs for children (5-point difference between C scores and V and I scores), showed no triangle scores in the first three grades. However, the data for grades 4-6 showed eight protocols with C scores significantly higher than I and V, and two with C

TABLE 2 Means and Standard Deviaiions for Adult and Grade School

Sub-sample Scaled Scores and Verbal IQs

Information Comprehension Vocabulary Verbal IQ Sample N (SD) ( S D ) ( S D ) (SD)

Triangle WAlS ‘76-’80 I

Non-Triangle WAlS ‘76-‘80

Grades 1-3 WISC-R ‘76-‘80

2

Grades 4-6 WISC-R ‘76-‘80

Grades 1-3 (1978) 3

Grades 4-6 (1978)

Triangles (4-6, 1978)

51 10.67

(2.18)

78 I I .22 (2.21)

64 13.1 I (2.27)

I00 12.64 (2.44)

(2.22) 98 12.98

I l l 13.07 (2.34)

10 11.70 (2.71)

15.47 (2.34)

12.50 (2.37)

13.02

(2.69)

13.96 (2.33)

13.40 (2.74) 14.18 (2.36)

17.60 (1.65)

11.18

(1.71)

I I .88 (2.33)

13.56 (2.83)

13.07 (2.22)

13.79

(2.53) 13.65 (2.19)

12.80 ( I .48)

114.41

(8.96)

I 12.88 (9.44)

118.00 ( 1 1 . 1 1 )

118.65 ( I 1.33)

119.14 ( 1 I .90)

121.26 ( 1 I .72)

123.40 (10.18)

Verbal Comprehension Factor 583

scores significantly lower. Correlations were not computed for this subsample because its size was too small for them to be meaningful.

The data for sample 3, the WISC-R scores of 219 grade-school children tested in the local school district in 1978 for possible inclusion in a program for the gifted and talented, were searched for triangle scores. None was found among the 98 protocols in grades 1-3, but 10 of the 121 protocols from grades 4-6 showed the pattern (see Table 2).

Because all triangle scores were identified on the basis of two-tailed probabilities, it was felt that they should occur with a frequency of much less than 5%. I n order to get an estimate of the incidence of triangle scores in the general population, the Psychological Corporation was contacted to obtain the standardization samples for the WAIS and WISC-R. The WAIS standardization sample was not available, but the WISC-R stan- dardization sample was obtained.

I n this standardization sample ( N = 2200), 1.5% of the total sample exhibited the triangle pattern, and this did not vary significantly as a function of age (1.2% under 9 and 1.8% for 9 and over) or environment (1.7% for urban and I .2% for rural). Treating the standardization sample as the best estimate of the concurrence (1.5%) of triangle scores in the population, the probabilities of obtaining the results observed in the two WISC-R samples of grades 4-6 were calculated using the binomial distribution. The probabilities of observing 8 or more triangle scores in Sample 2 where N = 100 (p = .004) and 10 or more triangle scores in Sample 3 where N = 121 @ <.001) are essentially zero.

According to Wechsler (1958, 1974), Matarazzo (1972). and Zimmerman and Woo- Sam (1973), comprehension scores are less dependent on formal education than are in- formation and vocabulary scores. Hence, comprehension scores significantly higher than those on information and vocabulary normally may be expected from persons with good native intellectual endowment who have had limited educational and cultural oppor- tunities. Therefore, it is puzzling to find this pattern among college students and children who are being considered for a program for the gifted and talented. Is Idaho such an isolated and backward state that many bright students-even college students-have educational and cultural deficits; is this finding merely a part of the widely deplored decline in educational standards nationally, or is some unknown factor operating to produce the “Idaho triangle” in verbal intelligence subscores? Data from other parts of the country are needed to answer this question.

REFERENCES BANNATYNE, A. (1971). BANNATYNE, A. (1974).

COHEN, J . (1957).

COHEN, J . (1959).

DAVIS, F. B. (1959).

KAUFMAN, A. S. (1975).

KAUFMAN, A. S. (1979). MATARAZZO, J . D. (1972).

Williams & Wilkins. NEWLAND, T. E., & SMITH, P. A. (1967).

the WISC and the WAIS. Journal of School Psychology, 2 , 122-127. WECHSLER, D. (1958).

Williams & Wilkins. WECHSLER, D. (1974).

Psychological Corporation. ZIMMERMAN, I . L., & WOO-SAM, J . M. (1973).

Scale, New York: Grune & Stratton.

Language, reading and learning disabilities. Springfield, IL: Charles C Thomas. Diagnosis: A note on recategorization of the WlSC scaled scores. Journal of Learn-

The factorial structure of the WAIS between early adulthood and old age. Journal ofCon-

The factorial structure of the WAIS at ages 7-6, 10-6, and 13-6. Journal ofConsulting

Interpretation of differences among averages and individual test scores. Journal of

Factor analysis of the WISC-R at eleven age levels between 6% and I6l/2 years. Jour-

ing Disabilities, 7, 272-274.

sulting Psychology, 21, 283-290.

Psychology, 23, 285-299.

Educational Psychology, 50, 162- 170.

nal of Consulting and Clinical Psychology, 43 . 135-147. Inteiligence testing with the WISC-R. New York: John Wiley.

Wechsler’s measurement and appraisal of adult intelligence. Baltimore, MD:

Statistically significant differences between subtest scaled scores on

The measurement and appraisal of adult intelligence (4th ed.). Baltimore, MD:

Manual for the Wechsler Intelligence Scale for Children-Revised. New York:

Clinical interpretation of the Wechsler Adult Intelligence