ABSTRACT
Ability grouping is the grouping of students by ability or attainment to optimize student achievement and simplify the planning and delivering of instruction. There are two basic types: within-class and between-class. Within-class ability grouping is forming small groups of students with similar abilities or attainment within a classroom. Between-class ability grouping is forming different classrooms of students with similar abilities or attainment. Both forms of ability grouping are popular, but also perilous: popular because they make instruction more efficient for teachers, but perilous because this simplification comes at a price. In extreme cases, ability grouping can lead to persistent student groupings, which creates strata in achievement and lifetime outcomes that are stark and often biased with regard to race, class, and gender. With mixed-ability groups, there are two keys: accurate knowledge of students’ abilities and a sufficient number of students of low-, moderate-, and high-abilities to evenly distribute across groups to prevent students from feeling isolated.
