When does cooperative learning increase student achievement

This article reviews research on the achievement effects of cooperative learning instructional methods, in which students work in small groups to learn academic materials. Methodologically adequate field experiments of at least 2 weeks' duration in regular elementary and secondary schools indicate that among cooperative learning methods in which students study the same material together) only methods that provide group rewards based on group members' individual learning consistently increase student achievement more than control methods. Cooperative learning methods in which each group member has a unique subtask have positive achievement effects only if group rewards are provided. Group rewards and individual accountability are held to be essential to the instructional effectiveness of cooperative learning methods. Over the past 30 years there has been a considerable quantity of research concerning the effects of cooperative, competitive, and individualistic incentive structures on individual and group productivity. A cooperative incentive structure is one in which two or more individuals are rewarded based on their performance as a group; a competitive incentive structure indicates that two or more individuals are compared with one another, and those performing best are rewarded; and an individualistic incentive structure is one in which individuals are rewarded based on their own performance, regardless of others' performances. The research on these incentive structures has been reviewed on several occasions (e.g., Johnson & Johnson, 1974; Michaels, 1977; MillerHSlavin, 1977). All of these reviewers agreed that research relating different incentive structures to performance produces inconsistent findings. Some studies find that cooperative incentive