Massive Open Online Courses (MOOCs) have attracted a considerable amount of interest within higher education, not least because of the unprecedented number of learners who take them, free of charge. Yet below these headline features lie important and challenging questions. Are MOOCs being designed in such a way that learners will benefit from studying through them? What principles of learning and teaching are emerging as indicators of quality? How can we know what learning is taking place, and from there identify MOOCs’ potential for future use in HE?