The present study hypothesized that requiring use of an integrated learning system (ILS) would yield a learning benefit in a classroom situation. Two sections of an introductory psychology course taught by the same instructor and using the same text and exams differed with respect to whether online quizzing and concept mastery exercises in an ILS were required or optional. Students in the ILS-required section received substantial course credit for achieving a criterion of 100% correct on each online quiz, with unlimited retakes, and mastery of 25 key concepts per chapter. Results showed better exam performance for the ILS-required class across items keyed to different levels in Bloom's taxonomy. Students in the ILS-optional class failed to use these online resources consistently, suggesting that graded incentives may be needed to justify their use in classroom situations.