This study investigates voluntary use of online study questions, the relationship of study question use to examination performance, and the relationship of aptitude to study question use following an initial phase during which students either received course points for passing mastery quizzes or for completing a designated number of study questions. The results indicate a) students who first received points for completing study questions later made greater voluntary use of study questions, b) less able readers made less voluntary use of study questions than more able readers, and c) less able readers performed better on course examinations when awarded course points for completing a required number of study questions rather than quizzes. (Contains 3 tables and 3 figures.)