This study compared high, moderate, and low procrastinators on their (1) frequency and nature of rationalizations to justify procrastination, (2) reported degree of self-regulation, and (3) grades in a web-based course with 216 performances, all with deadlines. One hundred and sixteen college students enrolled in a web-based "study skills" course completed a (1) 16-item Proscrastination Scale, used to identify them as high, moderate, or low procrastinators, (2) frequency of use questionnaire of 15 common rationalizations for procrastination, and (3) nine-item self-regulation scale. Following the course, students' grades were obtained. Because of the nature of performances, grades were far more objective than in a traditional course. On the total rationalization score, high and moderate procrastinators significantly exceeded low procrastinators, with "Im just waiting for the best time to do it" and "I know I can pull this out at the last minute" as most discriminating. On the total self-regulation score, significant differences in the expected order were found between all three procrastinator groups. On course grade, high procrastinators were significantly lower than either low or moderate procrastinators. (Contains 17 references.) (Author/GCP)