In an instructional experiment, I split students into three groups––no quiz, announced quiz, and pop quiz. I used the same instructional style and teaching materials (including the same textbook and handouts) with each of these three groups. I also gave the same two midterms and final exam to each group. There were no mandatory attendance policies or bonuses for attendance. The announced-quiz group took 10 quizzes, each worth 2.5 percent of the course grade.