The Diablo Valley College (California) Research Office assessed the variation of grades in multiple-section courses and its impact on the ability to predict student success. All classes selected for the study were general education offerings applicable for the Associate of Arts degree and/or transfer, and were taught by more than one instructor. A grade point average (GPA) was computed for each instructor with an A grade equal to 4 points, B=3, C=2, D=1, and F=0 and W (withdrawal)=1. The GPA's were compared for all instructors in each class, and variation was calculated once with W's included and once with W's excluded. Including W's, instructor GPA's varied by a low of 0.6% for an administration of justice course to a high of 18.1% for an anthropology course. Excluding W's, grade variations ranged from 0.2% for a history course to 23% for a physics course. Grading variation for a course did not appear to depend on the number of instructors teaching the course. Other predictor variables examined in the regression analyses of selected courses included student age, gender, ethnicity, educational level, work hours, cumulative GPA in other courses, and high school GPA. The study report includes graphs showing the results of regression analyses for particular courses. (ECC)