During the second unit of the course, which followed exam 1, the major topic was learning and behavior control. The students were invited to attend an extra lecture outside of the regularly scheduled class time. The instructor told the students that a: they could sign up for any of a variety of times, b: the lecture would be presented on videotape, c: the lecture would describe applications of behavior-modification techniques to clinical and personal problems, d: the material was optional and would not be tested directly on the next exam, and e: the discussion of the applications would probably help the students understand the basic principles that would be covered on the next
