Cooperative learning is an effective instructional approach that helps many more students learn at high levels. Cooperative learning involves placing students of different ability levels together in small groups and assigning them a specific task. Each group member has a role to fill in completing the activity. The most successful cooperative learning is grounded in research that proves its effectiveness. Edison teachers are trained in the cooperative learning model developed by Robert Slavin at Johns Hopkins University for use in their highly successful reading program, Success for All (also Edison's core program for teaching children to read). We have adopted Slavin's model because it stresses the three essential components of successful cooperative learning: group goals, individual accountability, and equal opportunities for success.