From Noncompetence to Exceptional Talent: Exploring the Range of Academic Achievement Within and Between Grade Levels

This article analyzes the magnitude of individual differences in academic achievement and their growth over the first 9 years of schooling. The author anchors the widening-gap phenomenon on the theoretical recognition of large individual differences in learning pace, which logically leads over time to an increasing gap in knowledge and skills between the fastest and slowest learners. The achievement data used as evidence were borrowed from the developmental standard score (SS) norms of the Iowa Tests of Basic Skills (ITBS; Hoover, Dunbar, & Frisbie, 2001). These norms reveal, among other things, that within most grade levels the range between the lowest and highest achievers exceeds the 8-year gap in knowledge between average 1st- and 9th-grade students. Moreover, the achievement gap widens by about 145% between grades 1 and 9. Parallel evidence suggests that standardized achievement test data probably underestimate the true differences. Because it ensues from stable individual differences in learning aptitude, educators should not perceive that widening achievement gap as a failure of the educational system, but should recognize it instead as a proof that all learners are given the opportunity to progress at their own learning pace.