This study was conducted to develop a statistical model of the influence of course characteristics on student ratings of instruction. Unique to this study was the inclusion of the student participation rate as a variable. Other course characteristics studied were: expected grade, attendance, grade point average, sex of students, reason for taking the course, academic field, student level, course level, major, and class size. Stepwise multiple regression analysis was employed using two measures of global ratings of instruction as criterion variables: 1) a single item rating the overall "favorable impression" the instructor had on the students (global), and 2) the average of twelve items rating the instructor's effectiveness (overall). Course averages or proportions were calculated for each variable. A model was developed using 1989 Fall Term data (952 courses), and tested using 1990 Fall Term data (1,052 courses) from Oregon State University. Results of the regression analysis showed that approximately 20% of the variance found in the equations could be explained by five variables: expected grade, participation rate, attendance, sex, and grade point average. Expected grade was by far the best predictor accounting for 13% to 14% of the variance (at least r=.36 with criterion variables). Participation rate accounted for as much as 3% of the variance (roughly r=.2) and contributed significantly to all four equations. A correlation of -.42 was found for participation rate and class size. Results suggest participation rate has a relationship with student ratings of instruction and further study is warranted. Reason and academic field also explained small significant amounts of the variance in at least one equation each. The results were determined to be reproducible; equations generated with the 1990 test data were very similar to the 1989 data. Very high correlations were found between the global and overall criterion variables (r> .95); the single item variable produced the same results as the average of twelve items. A significant correlation of more than .5 was found between academic field and sex of student. The 80% unexplained variance is discussed. / Graduation date: 1993