Some professors argue that it is possible to "buy" higher course evaluations by grading more leniently and requiring less work. This study investigated the relations of student effort, appropriateness of class difficulty, and course evaluations with a sample of 463 undergraduates from a mid-sized, Midwestern university. Findings support the treatment of difficulty appropriateness and student effort as distinct concepts. Results refute the grading leniency hypothesis. Consistent with cognitive dissonance theory and the validity hypothesis, student effort was positively related to all dimensions of course evaluation, and these relationships could not be explained by effort's relation to expected grades. Student effort was also significantly related to a number of student, instructor, and course characteristics. (Contains 2 tables.)