**Drill-Review Pairs**
This structure is useful for courses that require drill and practice. Four students are grouped together as two pairs. Each pair is given two problems to solve. The two students are assigned roles of explainer (the person who describes step-by-step how to do the problem) and an accuracy checker (the person who verifies the correctness of the methodology used to solve the problem and encourages the other student if needed). After the first problem is completed, the roles switch for the second problem. After both problems are finished, the two pairs of students re-group and review the two problems. If the four are in agreement, the group forms pairs again and continues solving more problems. If there is disagreement, the group reviews the problem and reaches consensus on the solution to the problem (Johnson, et al., 1998).

This structure can be beneficial following mini-lectures since it provides immediate reinforcement of any concepts or methodologies presented. When students are first learning a difficult concept they may need to help each other play the role of explainer.

Johnson, D. W., Johnson, R. T., and Smith, K. A. (1998). *Active learning: Cooperation in the college classroom*. Edina, MN: Interaction Book Company.