Psychology students frequently have misconceptions of basic concepts in operant conditioning. Prior classroom observations revealed that most students defined positive reinforcement as reward and equated negative reinforcement and punishment. Students also labeled positive reinforcement as rewarding good behavior and negative reinforcement as punishing bad behavior. We developed 14 problem-solving situations that involve positive reinforcement, negative reinforcement, and punishment. Students analyzed these situations in regular classroom sessions and as homework. In these exercises, students specified the discriminative stimuli, the responses, and the nature of the consequences. Correlated t tests on the pre- and posttest means indicated a significant increase in students' understanding of these concepts.