A comparison of the peabody individual achievement test, the metropolitan achievement test, and the otis-lennon mental ability test

In order to clarify the concurrent validity of the Peabody Individual Achievement Test (PIAT) and the Metropolitan Achievement Test (MAT), product-moment correlations were computed for all subscores and total scores for 26 normal-range public school third-grade girls and boys. The reading comprehension subtests correlated.81, spelling.88, and PIAT Mathematics with MAT Total Math.64. Correlations were computed for the Otis-Lennon Mental Ability Test and the PIAT General Information subtest as.77, and the Otis-Lennon and the PIAT Total Test scores as.79. Concurrent validity of the PIAT with both tests is tentatively considered adequate except in the area of mathematics, in which the PIAT, relative to the MAT, appears to be reflecting ability to handle math concepts (.68) more accurately than math computation (.41) or math problem solving (.56). Correlations with IQ partialed out suggest the PIAT Total Test, and PIAT and MAT reading and spelling measures, are relatively uninfluenced by IQ variations, whereas with IQ held constant, the weak positive correlations between the PIAT and MAT math subtests became essentially random relationships.