The present study investigated the effect of distributed versus crammed practice before a course deadline on the retention and transfer of knowledge, and whether learner characteristics moderate the effect. In Experiment 1, only 41% (N = 38) of the initially enrolled students worked the voluntary but recommended practice tasks. Moreover, markedly fewer students did so in the distributed condition (12%) than the crammed practice condition (29%). In Experiment 2, working the practice tasks was mandatory and more students ...