Questionnaire surveys have found a strong relationship between students' perceptions of their courses and their approaches to studying, but this might result from the operation of response biases. Responses to the Course Experience Questionnaire and the Revised Approaches to Studying Inventory from 2137 students taking seven courses by distance learning were reanalysed. Both acquiescent responding and extreme responding were found to be consistent traits within individual students between the two instruments. When these were statistically controlled, the overlap in variance between the students' scores on the two instruments was reduced from 45.3% to 31.9%, and the variation in the students' course marks explained by their scores on the two instruments was reduced from 21.8% to 18.9%. Nevertheless, the relationship between the two sets of scores remained the same: students who rated their course positively were more likely to show desirable approaches to studying and less likely to show undesirable approaches. (Contains 9 tables.)