Formal cooperative learning involves students working in groups for one class period to several weeks to achieve shared academic goals and complete assignments together. The teacher's role includes forming groups, explaining tasks and expectations, monitoring groups, and assessing student learning and the group process. Informal cooperative learning uses brief temporary groups to actively engage students during lectures through focused discussions before, during, and after to process material. Cooperative base groups are long-term heterogeneous groups that provide academic and social support to members.