A longitudinal study was conducted at William Rainey Harper College, in Palatine, Illinois, to observe the performance and achievement of all credit students entering the college from fall 1979 through fall 1989. Academic records were analyzed for 14,908 full-time and 30,082 part-time students. Study findings included the following: (1) over the years, the grade point average (GPA) of the student body rose and fell in direct relationship to changes in the grading policy; (2) full-time students entering before they were 21 years old had average GPA's of 2.31, while students 21 or older averaged 2.6; (3) part-time students who entered before they were 21 averaged a 1.88 GPA, while those entering between the ages of 21 and 34 averaged 2.43, and those 35 or older averaged 2.83; (4) full-time student GPA's by ethnic group were 2.38 for Asians, 2.35 for Whites, and 1.82 for Blacks/Hispanics; (5) part-time student GPA's were 2.32 for Whites, 2.11 for Asians, and 1.79 for Blacks/Hispanics; (6) full-time students were equally divided by gender; (7) career program enrollments were 58% female, while transfer program enrollments were 54% male; (8) students who began full-time completed an average of 42 credits, while part-time students completed an average of 15 credits; (9) women were more likely than men to obtain degrees; (10) the persistence rate (for those who started one fall semester and returned one year or more later) was about 80% for full-time students and 55% for part-time students; and (11) most full-time students entered with a transfer program major, while greater numbers of females, older students, and minorities enrolled in career programs. (PAA)