- High achievement benefits males more than females in the assignment process.
- Teachers do consider sex in assigning students to the high-ability group and that high-achieving males are given an advantage over high-achieving females.
- Ability grouping for mathematics instruction has no direct effect on gains in mathematics.
- The percentage of blacks in the class has no effect on math achievement in ability grouped classes. This is probably due to the resegregation of students into ability groups, which is due to the correlation between race and achievement.
- Ability grouping has no main effect on mathematics achievement.
- Sex is a factor in the assignment of students to ability groups: Males are more likely than females to be assigned to the high-ability group. Nevertheless, the analyses do not reveal an effect of ability group level on growth in mathematics achievement.
- Find no advantage of being in the high-ability group and no disadvantage of being in the low-ability group.