Effects of Ability Grouping on Growth in Academic Achievement

This paper applies a theory of growth in academic achievement to the study of the effects of ability grouping on reading achievement. The theory sees students’ ability and effort determining how they utilize opportunities for learning provided by instruction. The mathematical specification of the theory allows for the estimation of models that show (a) ability grouping provides fewer opportunities for learning than whole class instruction but greater utilization of those opportunities; (b) high ability groups provide more opportunities than low groups; and (c) small homogeneous groups facilitate reading achievement more than larger, more heterogeneous groups.