Use Contrasting Cases
Help students develop more sophisticated ways of organizing knowledge, by presenting contrasting cases, or two items that share features but differ in critical ways. Although cases are often used in teaching, they tend to be most effective when presented with some compare and contrast analysis versus in isolation.
Ambrose, S.A., Bridges, M.W., DiPietro, M., Lovett,M.C., & Norman, M.K. (2010). How learning works: Seven research-based principles for smart teaching. San Francisco, CA: Jossey-Bass.