Problem solving followed by explicit instruction, as suggested by productive failure and several other instructional theories, indicates long-term learning benefits, whereas explicit instruction followed by problem solving has been consistently demonstrated as superior within the framework of cognitive load theory. However, the effectiveness of these instructional approaches may be moderated by several factors such as levels of element interactivity of learning materials, types of knowledge involved, and levels of learner prior knowledge (expertise). This review systematically searched studies comparing these alternative sequences, computed the observed effect sizes, and explored the effects of element interactivity, types of knowledge, and levels of expertise on the effectiveness of two instructional approaches.