- There is a relationship between school SES and math and science.
- About 40% of the schools use ability grouping for 7th grade science and over 80% group math.
- Nongrouped students in science are less likely to be Black or Hispanic; in math, non-groupred students have somewhat lower average SES.
- Results of ability grouping in middle school science generally confirm the differential benefits theory, but mainly in a negative direction. The effects of high group placement are negligible in seventh grade and positive but still not strong at the eight-grade level.
- In math, the differential-effects theory is clearly supported. High group students learn substantially more than nongrouped students and low-group students learn much less.
- Ability grouping thus appears to benefit advanced students, to harm slower students, and to have a negligible overall effect as the benefits and liabilities cancel each other out.
- Grouping has no significant overall benefits in either science or mathematics.
- Ability grouping in 7th and 8th grade mathematics and science is clearly not an optimal arrangement compared with the nongrouped alternative, for low-group students are significant losers.
- Conditions under which grouping benefits all students do not generally exist.