The Peabody Picture Vocabulary Test and Naive Versus Trained Examiners.

The Peabody Picture Vocabulary Test is marketed as an instrument suitable for use by persons without special training in testing. A total of forty children, ranging from retarded to gifted, were tested in counter balanced order by eight elementary school teachers and by three school psychologists. No significant differences between the S's mean I.Q. 's in the experienced versus the naive examiner's data were found and there were no significant treatment effects, trial effects or interactions. However, differences in the test results for certain individuals were large suggesting the necessity for cautious use in the absence of corroborating data. THE PEABODY PICTURE Vocabulary Test is described as a psychometric instrument designed to provide an estimate of verbal intelligence through the measurement of the S's hearing vocabulary (2) . This is accomplished at the most rudimentary response level, namely simple recognition. The S can make the necessary instrumental response if he has some voluntary motor movement. The time required by the Peabody probably rarely exceeds 15 minutes. Other advantages of the instrument include the pro vision of alternate forms, objective scoring criteria, and its non-threatening nature even with the most fearful children. The very nature of the advantages of the Peabody suggest also some of its recognized limitations. For instance, most examiners make use of the tables provided by the user's manual to convert raw scores into I.Q. equivalents. The implication is, of course, that the results are generally comparable to other recognized methods of obtaining intelligence quotients. However, the nonprofessional user may not appreciate the fact that he has measured only a small part of the domain of general intelligence. Recognition vocabulary is important in intellectual functioning. However, it does not by any stretch of the imagination cover the full range of measurable cognitive behavior. Many users would probably prefer that the resulting scores from the Peabody be characterized as a "language age" or quotient. However, the published research on the instru ment as it is used to assess general intelligence is favorable. For the most part, researchers report reasonably high correlations between Peabody Picture Vocabulary Test scores and scores from well established instruments measuring general intelligence such as the Binet and WISC (1, 3, 4) . One of the major advantages of the Peabody Picture Vocabulary Test reported by its author is that its administration requires no special training or competency on the part of the examiner to get reliable results. He makes the point that a potential examiner should be thoroughly familiar with the test material, have practice in using it and follow instruc tions carefully. According to the author, "If all the instructions are strictly observed, psychologists, teachers, speech therapists, physicians, counselors, and social workers should be able to give the scale accurately (2) . " We could find no published evidence to support this assertion. Since this instrument is widely used by examiners that school psychologists would characterize as "untrained" or "naive, " we proposed to determine if one of the categories of "naive" examiners suggested by the author of the test could indeed secure reliable results with the Peabody. This content downloaded from 157.55. 39.78 on Wed, 22 Jun 2016 05:25:59 UTC All use subject to http://about.jstor. org/terms 28 THE JOURNAL OF EXPERIMENTAL EDUCATION