The present research attempted to determine if tests can serve as teaching devices by comparing student achievement in classes where several examinations were administered. Students in ten classes of introductory psychology served as subjects in the study. Three classes received weekly, teacher-made quizzes of 15 multiple-choice items; four classes received no examinations; three classes received three tests. The findings provide a basis for the more frequent use of examinations in teaching psychology. Examinations, or more precisely, the study they force, enables students to review and recapitulate material between classes. Although students in the weekly-tested groups did not particularly like quizzes every week, they were glad at the end of the semester that they had been tested so frequently. (BW)