Without the cooperation of its members society cannot survive, and the society of man has survived because the cooperativeness of its members made survival possible…. It was not an advantageous individual here and there who did so, but the group. In human societies the individuals who are most likely to survive are those who are best enabled to do so by their group.
David W. and Roger T. Johnson
Cooperative learning may be broadly defined as any type of classroom grouping in which students of all levels of performance work together in structured groups toward a shared or common goal.