Comparison of the PPVT-R and WISC-R with urban educable mentally retarded students

Abstract

Comparisons of the revised PPVT (PPVT-R) and the WISC-R were made with 67 EMR students. Significant differences were found between the PPVT-R mean standard scores and Verbal, Performance, and Full Scale IQs. The PPVT-R did not correlate significantly with the WISC-R scales or subtests, suggesting the tests are measuring different abilities.The Peabody Picture Vocabulary Test (PPVT; Dunn, 1959) has been widely used by psychologists, speech and hearing specialists, and educators for over 20 years. The PPVT is a popular instrument because it is a brief, easily administered test that requires little or no vocalization from the individual being tested. These characteristics, as well as the wide range of ages for which the PPVT is applicable, have made the instrument extremely well suited for testing EMR students.Previous studies have been conducted to determine the comparability of scores attained on the PPVT and the WISC-R. These studies have demonstrated consistently that the PPVT overestimates the intellectual abilities of EMR individuals by approximately 6 to 12 IQ points as measured by the WISC-R (Covin, 1976; Hodapp & Hodapp, 1980;Vance, Prichard, & Wallbrown, 1978). The PPVT has been revised recently (PPVT-R; Dunn, 1980) and will no doubt continue to be used with EMR individuals. The focus of this study was to compare scores attained on the PPVT-R and the WISC-R for urban EMR children. METHOD SubjectsThe 67 students (32 females and 35 males) participating in this study included blacks, Hispanics, and whites all previously identified as Educable Mentally Retarded and enrolled in EMR programs in a large city school system located in the Midwest. The students ranged in age from 7-3 to 15-8, with a mean of 11.25 years.All of the black and white students were selected on a random basis from computer listings of students enrolled in EMR programs. Since the population of Hispanic EMR students was smaller than the black and white groups, participation of all Hispanic EMR children was solicited. The sample included in this study represents all students whose parents gave permission for their child's participation and who were placed in EMR programs as a result of their scores on the WISC-R. InstrumentsThe PPVT (Dunn, 1959) is a receptive vocabulary test appropriate for individuals between 21 months and 18 years of age. The test format requires that the examiner disRequests for reprints should be sent to David P. Prasse, School of Education, Dept. of Educational Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53201. assistance in data collection, and to the American Guidance Service for their assistance. 'The authors wish to extend their appreciation to Ms. Vicki Jernigan and Mr. Greg Brock for their 174

An exploratory investigation to detect cross-cultural differences on the PPVT-R

“…This revised Peabody (PPVT-R) has attracted much research attention, with studies of concurrent validity of the PPVT-R and the McCarthy Scales (Ferrari, 1980;Gullo & Mcloughlin, 1982;Naglieri, 1981), the PPVT and the PPVT-R with normal preschool children (Choong & McMahon, 1983;Naglieri & Naglieri, 1981), with gifted children (Karnes, McCallum, & Bracken, 1982;Pedriana & Bracken, 1982), with autistic children (Ferrari, 1980), and with urban educable mentally retarded students (Prasse & Bracken, 1981). In an interesting cross-cultural study, McCallum and Bracken (1981) found no significant differences between scores on the two forms (L and M) of the PPVT-R for whites, males, females, and the total group, but noted that "black preschool children may systematically earn higher scores on Form M than on Form L" (p.424).…”

Use of the WISC-R and PPVT-R with mentally retarded children

“…While these findings are consistent with Naglieri (1981) , they appear contrary to Prassee and Bracken's (1981) report of no significant PPVT-R/WISC-R correlations. However, they are not.…”

“…Only a few studies have examined the relationship between the PPVT-R and intelligence tests. Prassee and Bracken (1981) report that the PPVT-R was not correlated significantly with the WISC-R's Verbal, Performance, or Full Scale I& scores and yielded a significantly lower mean score for a sample of mentally retarded children. The difference in mean scores between the Peabody and intelligence tests is consistent with previous findings with the PPVT, but in the opposite direction; the PPVT tended to overestimate and Prassee and Bracken found that the PPVT-R underestimated I& scores.…”

A comparison of preschool scores on the PPVT-R and the TELD

“…In a study by Naglieri (1981) formance .27, and Motor .23). These correlations were much higher than those between the PPVT and MSCA in Taylor's (1979) Prasse and Bracken (1981) compared the performances of 67 Black, Hispanic, and White EMR students on the PPVT-R and the Wechsler Intelligence Scale for Children-Revised -WISC-R (Wechsler, 1974). The children ranged in age from 7-3 to 15-8 years.…”

“…Naglieri (1981) warned that the PPVT-R should not be used as a substitute for the MSCA, and, additionally, he has noted that the PPVT-R may be more appropriate as a brief measure of verbal comprehension. Breen (1981) and Prasse and Bracken (1981) compared standard scores from the Wechsler Intelligence Scale for Children-Revised -WISC-R (Wechsler, 1974) with standard scores of the PPVT-R and found that the PPVT-R underestimates the intellectual abilities of preschool children. They concluded that the PPVT-R should not be used as an intelligence measure.…”