This special issue on cognitive load theory is a collection of eight papers that report either on contemporary challenges to the theory that may lead to new research directions or on new research directions that pose new challenges to the theory. The contemporary challenges relate to the timing and frequency of cognitive load measurement, the design of instructional animations, and the use of eye tracking to uncover learners' cognitive processes. The new research directions relate to fostering learning by directing novices to use primary knowledge, instructing novices to self-manage their cognitive load, and considering learners' affective responses to different configurations of simple and complex tasks. We hope that the findings of these studies will instigate other researchers to pursue new research directions and meet its challenges.