Nearly 50 years ago, a program of Lewinian "action research" explored the most effective way to respond to Prejudiced comments (Citron, Chein, & Harding, 1950). In this article, I describe a classroom adaptation of that research in which students receive 10 scenarios involving a prejudiced comment and rotate playing 1 of 3 roles (prejudiced speaker, responder, or social observer) in a mock interaction. The result is a dramatic example of "action teaching in which students learn not only about social psychology but also about ways to address an important social problem.