- Average-ability students from homogeneous groups outperformed their heterogeneously grouped counterparts. This superiority was reversed for low-ability students; They achieved higher scores when learning mixed-ability groups.
- Heterogeneously grouped low-ability students thought more positively of collaborative learning than low-ability students from homogeneous groups. For average and high-ability students, motivation scores differed in favor of the homogenous groups, but this effect did not reach statistical significance.
- On the group assignment, heterogeneous groups outperformed homogenously grouped low and average-ability students, but performed as well as homogenous groups of high ability students.
- Group composition also affects the nature of the learning dialogue. Homogenous grouping yields higher proportions of collaborative elaborations. Compared with heterogeneous groups, students of similar ability more often complement and build on each other’s thoughts when answering questions, resolving conflicts, or reasoning about the course content.
- As with learning outcomes, group composition has a differential effect on students’ motivational beliefs. Low-ability students are more motivated to learn in heterogeneous groups; the ratings of average and high-ability students does not differ as a function of group composition.
- Using heterogeneous grouping for high-ability students does not affect achievement or motivation. However, heterogeneous grouping does hold back average-ability students.
- Low-ability students achieve more and are more motivated to learn in heterogeneous groups. Average-ability students perform better in homogenous groups whereas high-ability students who equally strong learning outcomes in homogenous and heterogeneous groups.