Stability, concurrent and predictive validity of the PPVT-R

Explored the relationship between the Peabody Picture Vocabulary Test-Revised (PPVT-R) and the Peabody Individual Achievement Test (PIAT), and pretest PPVT-R standard scores administered about 7 months earlier for a sample of 29 mentally retarded children between the ages of 5-5 and 12-7 (mean = 9-6, SD = 1-11). Pretest PPVT-R scores correlated moderately with PIAT standard scores (Median r = .43) and with posttest PPVT-R scores (r = .81). There was no significant difference between the mean pre and post PPVT-R scores (60.3 and 58.5, respectively). The PPVT-R and PIAT Total Test Score administered in the same session correlated .71 (Median r with the PIAT's subtests = .64). Implications are discussed in light of the stability and predictive and concurrent validity of the PPVT-R for this sample.