A comparison of the PIAT and WRAT: A closer look

Abstract

A sample of 46 white fourth-grade pupils was administered the PPVT, WRAT, and PIAT, except for PIAT Reading Comprehension and General Information. Subjects were selected randomly from those pupils whom classroom teachers judged to be doing at least average academic work. Mean grade equivalents, as well as intercorrelations, were examined for PIAT and WRAT subtests. No sex differences were found for PPVT IQ, age, or most achievement scores. Mean grade equivalents generally ranged between the sixth-and seventh-grade levels. Nearly all PIAT-WRAT intercorrelations were positive and significant, and highest for the similarly labelled subtests. Substantial differences were noted in mean grade equivalents. WRAT Reading and Spelling exceeded their PIAT counterparts by approximately one grade level. In contrast, PIAT Mathematics exceeded WRAT Arithmetic by more than one grade level. The possible effects of differences in item content and task structures on performance were discussed. Implications for practitioners involved in psychoeducational evaluations were considered.