We have studied the types of student teams that are most effective for collaborative learning in a large freshman university physics course. We compared teams in which the students were all of roughly equal ability to teams with a mix of student abilities, we compared teams with three members to teams with four members, and we examined teams with…

Two social psychological theories--similarity theory and equity theory--are employed to elucidate the relationship between group members' abilities and group performance on tasks involving high levels of interdependence. Contrasting hypotheses are drawn regarding specific ability compositions that should evoke performance above or below the simple…