- The most intensive use of within-class ability grouping exists in schools that serve high proportions of minority students and in schools with high variability in students’ reading readiness.
- Schools serving primarily minority students that use within-class ability grouping have higher average gains in reading achievement by the end of the school year than comparable schools that do not use this form of grouping. Use of this instructional practice is not associated with increases in average achievement gain scores for schools serving students of diverse or primarily White backgrounds.
- The most common from of ability grouping that kindergartners experience is within-class ability grouping.
- As the minority concentration of the school’s student body increases, so does use of within-class ability grouping. Use of this instructional practice is highest among diverse and high-minority schools. The schools least likely to use this form of grouping in kindergarten are those serving primarily White students.
- The expectation that diverse or high-minority schools might use within-class ability grouping because of lack or resources or because of the other structural characteristics introduced in the analysis is not supported by these results.