The temporal stability of the PPVT, Form B, was investigated for two age groups from regular normal and special education classes (EMRs). The second administration of the test occurred 6 mo. after the first, following summer holidays. Analysis indicated that only the older normal Ss showed significant changes in MA, gaining 14 mo. Test-retest correlations ranged from .66 to .92.
DunnL. M.BrooksS.Peabody Picture Vocabulary Test performance of educable mentally retarded. Training School Bulletin, 1960, 57, 35–40.
3.
KahnH.Evidence for long-term reliability of the PPVT with adolescent and young adult retardates. American Journal of Mental Deficiency, 1966, 70, 895–898.
4.
WinerB. J.Statistical principles in experimental design. New York: McGraw-Hill, 1962.
