Over a three-semester period in a large undergraduate human development course, students were assigned to 5-7 member groups to work together in preparing for an exam in one of the five content units in the course. Their exam performance was tracked over three units: a baseline unit in which students worked only individually, a unit in which they worked in cooperative teams, and a follow-up unit in which the formal cooperative team structure was removed. Three different bonus-credit contingencies were used in the cooperative learning unit across the three semesters: (a) awarding full bonus credit to each individual in the group if the group as a whole improved its exam performance by the specified amount, (b) awarding partial bonus credit to each individual in the group if the group as a whole improved it exam performance by the specified amount and full bonus credit to each individual who also improved by the specified amount, and (c) awarding full bonus credit to an individual in the group if both the group and the individual improved exam performance by the specified amount. The three contingencies produced somewhat similar patterns of change for low and average performers, but the high performers fared better under the last two contingencies than under the group-only contingency.