Peabody Picture Vocabulary Test
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The PPVT-IV, updated in 2007, is an untimed test of receptive vocabulary for Standard American English and provides a quick estimate of verbal ability and scholastic aptitude. It was created in 1959 by two pioneers in special education, Lloyd M. Dunn and Leota M. Dunn. The current version lists L.M. Dunn and his son D.M. Dunn as authors.
The test is given verbally and takes about 20–30 minutes. No reading is required by the individual, and scoring is rapid and objective. For its administration, the examiner presents a series of pictures to each person. There are four pictures to a page, and each is numbered. The examiner states a word describing one of the pictures and asks the individual to point to or say the number of the picture that the word describes. Item responses can also be made by multiple choice selection depending on the age of the person being tested. The total score can be converted to a percentile rank, mental age, or a standard deviation IQ score. Although desirable, no special training is required to properly administer and score the PPVT-III. However, anyone interpreting or explaining the test scores should have knowledge in psychological testing and statistics. Tests the ‘Lexical Retrieval Hypothesis” - that gestures help to access words for speech production
The national norms of the PPVT-III were extended to include ages 2–6 to 90+ years of age. This edition also was developed from adult norms obtained on 828 persons ages 19 to 40 selected to be nationally representative of geographical regions and major occupational groups. No people with handicaps were included in the norm population.
Two parallel forms (A and B) can be used for testing and retesting.
The PPVT-IV provides an estimate of the client's verbal intelligence and has been administered to groups who had reading or speech problems, had mental retardation, or were emotionally withdrawn. Because the manner of the individual's response to stimulus vocabulary is to point in any fashion to one of four pictures that best fits the stimulus work, these tests also apply to rehabilitation of individuals who have multiple physical impairments, but whose hearing and vision are intact. The test also has high interest value, and this can establish good rapport with a tested individual.
The PPVT-IV can also be used for assessing the English vocabulary of non-English-speaking individuals and assessing adult verbal ability.
The test is not useful in its present form for blind and deaf people, but can be useful for people with intellectual disability, for whom no modifications in instructions or format are needed. The only possible problem is that the illustrations for about the first 50 items typically feature children, and thus may not be appropriate for adult subjects with intellectual disability.