Student performance in a self-paced personalized system of instruction course is varied in rates and patterns of work. Using 118 students in a college level introductory psychology course the investigators found 1) students worked at a variety of rates and patterns; 2) students who started to work early had a much greater chance of finishing the course than those who started later; and 3) that most students who made long pauses did so after taking one of the first four written exams regardless of when in the course they started to work. The implication presented was that a student should be reinforced for starting work early in a self-paced class. (MC)