A classroom field experiment was conducted on the effects of preparation homework and practice homework on student achievement in a fifth-grade social studies class, when used in conjunction with cooperative learning. The study investigated whether cooperative learning with or without preparation or practice homework produces greater student achievement, and whether student achievement levels were the same regardless of type of homework assigned. Subjects (N=64) were enrolled in four fifth-grade classes with teachers trained in cooperative learning. Two classes were assigned to a no-homework condition, one was placed in the practice homework condition, and the remaining class was in the preparation homework condition. A pretest/posttest was developed and administered to all students. Results suggest that the group of students doing cooperative learning, with the addition of homework, produced greater academic achievement than the group doing cooperative learning alone. No significant differences were found between the practice homework group and the preparation homework group. Appendices include reading assignments and cooperative learning activities, homework assignments, a copy of the test, and analysis of the raw data. (LL)