While allocation to ability groups and curriculum tracks is ostensibly based on students' aptitude for learning, previous research has found that student aptitude explains only a small portion of the variance in curriculum placement. Likewise, while ability grouping has been described in curriculum theory as being very flexible, studies have found that, in practice, little movement occurs between groups. This study examines ability grouping in a first‐grade classroom in order to increase our understanding of the factors which influence ability group formation and maintenance at the very beginning of children's school careers.

I will show in this chapter that time and management constraints influence the number and size of groups formed independently of the range of aptitude in the classroom. Since these factors remain constant throughout the year, they also limit the amount of movement that occurs between groups. These group assignments over time become a part of the record that follows individual children throughout their institutional life careers (Mehan et al. 1983). Placements made in elementary grades, where aptitude boundaries appear more flexible, then become even stronger determinants of potential placement in later schooling. Although at the high school level, other constraints are likely to affect allocation decisions by virtue of the degree of selectivity throughout schooling, early placement decisions are likely to influence later outcomes. While it can be argued that these constraints represent a general problem which exists whenever there is an attempt to match individuals with positions in society, it is on schooling, as the legitimized preparation for future life career chances, that concern over allocation is likely to concentrate.