This experimental study investigated the mechanisms by which learner control influences learning in an e-learning environment. The authors hypothesized that learner control would enhance learning indirectly through its effect on trainee reactions and learner engagement (in particular, off-task attention), such that learners who were more satisfied with the training and devoted more cognitive resources toward the instructional content versus off-task thoughts would possess greater posttraining knowledge. The study also examined the role of individual differences (training motivation and goal orientation) in the prediction of these 2 mediating variables. A sample of 274 undergraduates completed an e-learning program, either with or without interactive, learner control tools. Results suggest that both training satisfaction and off-task attention predicted subsequent learning. Learner control had a positive impact on training satisfaction but was not related to off-task attention. The individual difference variables had a differential impact on the mediating variables. In particular, performance orientation was linked to off-task attention, whereas mastery orientation was found to indirectly influence satisfaction via its direct effect on training motivation. Implications for the design and further study of e-learning are discussed. (Contains 2 footnotes, 3 tables, and 2 figures.)