The mean IQ on the Slosson Intelligence Test (SIT) was substantially higher than expected based on the earlier Peabody Picture Vocabulary Test (PPVT) scores. Sampling error and examiner error were excluded as explanations. Results suggest that the PPVT and SIT yield different scores and lack comparability. (Author)

Examines issues related to the measurement of potential learning problems of young children. Looks at the rationale for screening, the instability of behavior, the use of inappropriate measures; defines the "at-risk" population, and problems in prediction. Presents a method for calculating the predictive validity of a screening measure. (RJM)