Courses using a Personalized System of Instruction (PSI) have proliferated in the past decade. Researchers have explored various factors related to PSI, but rarely, if ever, have students' study habits or preferences been considered. A questionnaire examining the study habits, exam preferences and attitudes toward various instructional formats was administered to 762 introductory psychology students enrolled in either lecture/seminar or PSI sections. Analyses comparing methods revealed different behavioral patterns for students who performed well under PSI and lecture/seminar formats. Successful PSI students were orderly, systematic hard workers who emphasized the printed word; they believed that the PSI method would produce higher grades. Successful lecture/seminar students focused their studying to the time prior to performance events, required aid in organizing course material and were as concerned with the spoken as with the written word. Science students gravitated toward PSI while Arts/Humanities students prefered lecture/seminar courses. The findings suggest that PSI is personalized for some, but not all, students. (The survey instrument is included in the appendix.) (Author/NRB)