This study focuses on learning in three different hypermedia environments that either support autonomous learning, learner-controlled learning or system-controlled learning and explores the mediating role of academic self-regulation style (ASRS; i.e. a macro level of motivation) on learning. This research was performed to gain more insight in the conditions under which learning in hypermedia environments is effective. Sixty-nine grade five students from a primary school answered short essay questions using video material from a hypermedia environment. The effects on task motivation and test performance were measured. It was found that learners in the autonomy supported hypermedia environment reported lower levels of controlled task motivation, compared to the learners in the system-controlled and learner-controlled hypermedia environments. But there were no effects of hypermedia environment on autonomous task motivation or the reported need fulfilment for autonomy. Furthermore, learners in the learner-controlled hypermedia environment scored lower on a delayed, In-Depth Knowledge Test compared to learners in the other two environments. Moreover, learners in the autonomy supported hypermedia environment watched more (unique) videos compared to learners in the system-controlled and the learner-controlled hypermedia environments. As for the role of learners' ASRS, we found no interaction with the type of hypermedia environment on task motivation or performance. Learners' ASRS did, however, affect the learners' motivation for the task. And, when presented with advice (as in the autonomy supported hypermedia environment) learners with an autonomous self-regulation style followed more advice, compared to learners with a more controlled self-regulation style. [ABSTRACT FROM PUBLISHER]