Saving Time: Using The Peabody Picture Vocabulary Test-Iii As A Screening Test Of Intelligence With Undergraduates

College Student Journal, June, 2000 by Howard Carvajal, Sheryl J. Nowak, Amy C. Fraas, Margaret A. Mcconnell

Most college and university counseling centers are overwhelmed with traditional clients. There is also an increased number of students with disabilities. Being able to screen students accurately and efficiently would save precious time. The Peabody Picture Vocabulary Test-III and the Wechsler Adult Intelligence Scale-III were given to 31 students (14 men, 17 women; 18-21 yr. old) who were enrolled in introductory psychology classes at a Midwestern university. The statistically significant correlations of .74, .67, .76, and .79, respectively, between the Peabody Standard Score Equivalents and the Wechsler Verbal and Full Scale IQs, Verbal Comprehension Index scores, and Vocabulary subtest scores suggest that the Peabody is a satisfactory screening test of intelligence for use with undergraduate college and university students.

Time is precious! Most college and university counseling centers are overwhelmed with clients. In addition to serving the traditional clientele, there is an increased number of students with disabilities who often need to be evaluated. Being able to screen students accurately and efficiently would help save that precious commodity, time.

The Peabody Picture Vocabulary Test-III (PPVT-III; Dunn & Dunn, 1997) is a measure of receptive vocabulary and-is designed to be administered to children as young as 2 1/2 years as well as to mature adults. The Peabody series has been used primarily as a screening device to measure intelligence. Fifteen minutes or less is required for the administration of the PPVT-III. The Wechsler Adult Intelligence Scale-III (WAIS-III; Wechsler, 1997) is designed to be administered to individuals 16-89 years old with administration time approximately 75-90 minutes. Since 1939 with the publication of the Wechsler-Bellevue Intelligence Scale, the Wechsler has been the test by which all adult intelligence tests are judged. The earlier editions replaced by the PPVT-III and the WAIS-III ranked in the top 7 in frequency of mention of use among instruments of all types by psychologists in a wide variety of settings (Lubin, Larsen, & Matarazzo, 1984). The trust placed in these two instruments is obvious.

Because both tests were revised and published in 1997, the authors had little, if any, opportunity to determine the relationships between the two new revisions; therefore, this study was undertaken to supply some preliminary data about the concurrent criterion-related validity of the two revisions. Specifically, answers to three questions were sought: (1) What are the correlations between the WAIS-III Verbal (V), Performance (P), and Full Scale (FS) IQs and the PPVT-III Standard Score Equivalents (SSE)? (2) What is the correlation between the WAIS-III Verbal Comprehension Index (VCI), which is comprised of the Vocabulary, Similarities, and Information subtests, and the PPVT-III SSE? (3) What is the correlation between the WAIS-III Vocabulary subtest score and the PPVT-III SSE?

Method

Participants

The participants included 31 undergraduates (14 men, 17 women; 18-21 years old) from a Midwestern university of approximately 5,400 students. The sample consisted of one Hispanic woman and 30 Caucasian men and women. The students were volunteers from general education psychology classes and earned required research credit for the course by their participation.

Testing Instruments

The regular battery of the WAIS-III was given; the V, P, and FS IQs and the VCI have means of 100 and standard deviations of 15. The WAIS-III Vocabulary subtest has a mean and standard deviation of 10 and 3, respectively. Form III-A of the PPVT-III was given to each participant; it has a mean of 100 and a standard deviation of 15. The testing was conducted during a three month period in the spring 1998 semester in a counterbalanced sequence.

Procedure

Second-year graduate students under the direct supervision of the professor who teaches the Wechsler course administered the WAIS-III, and the PPVT-III was given by an assistant professor. The tests were given in rooms specifically designed and equipped for testing.

Results

The descriptive statistics are shown in Table 1. The means of the scores were above those of the normative samples, and the standard deviations were a little smaller than the normative groups. Four of the five correlations between the WAIS-III scores and the PPVT-III SSE were statistically significant at the .01 level (see Table 2).

Table 1
Descriptive Statistics for the WAIS-III and the PPVT-III

Test                             M       SD

WAIS-III
  Verbal IQ                    113.0   13.0
  Performance IQ               114.6   10.8
  Full Scale IQ                114.8   11.3
  Verbal Comprehension Index   113.2   12.9
  Vocabulary                    12.6    2.5
PPVT-III
  Standard Score Equivalents   112.0   10.4
Table 2
Correlations for the WAIS-III and the PPVT-III Scores

Test

WAIS-III          VIQ     PIQ     FSIQ     VCI     Vocab
PPVT-III (SSE)   .74(*)   0.32   .67(*)   .76(*)   .79(*)

(*) p < .01