At the beginning of the semester, 2 introductory psychology classes took 1 pretest requiring them to match 12 psychological disorders with the correct definitions and another requiring them to match the disorders with appropriate examples. Twelve weeks later, both classes heard lecture material on the disorders. One class also performed an exercise in which students wrote an original example of each disorder. At the end of the period in each class, students took posttests identical to the pretests. The lecture-plus-exercise class performed significantly better than the lecture-only class on the posttests but not on the pretests, reflecting the teaching effectiveness of the exemplification exercise as a supplement to lecture material. (Contains 2 notes and 1 table.)