This paper reviews the role of intrinsic and extrinsic motivation in children's learning. The paper contends that two types of learning exist: self-initiated learning which is intrinsically motivated, and learning initiated by another person which involves external rewards. The paper suggests that motivation is not unidimensional and that task performance reflects the motivational system involved. The paper reviews early and current research on the effects of rewards on motivation which suggest that, for educational purposes, rewards limit a student's engagement in an activity, affect what is learned, and affect a student's desire to return to the activity involved. It is also suggested that rewards have undesirable effects on the teachers who dispense them. The paper contends that education should focus more on children's intrinsic motivation for learning. A variety of research is reviewed which highlights the child's intrinsic motivation to pursue questions of patterns and regularities in the world and related causal explanations. Also reviewed are studies which focus on the child's intrinsic desire to explore solutions to new problems and to relate new information to previously acquired knowledge. The paper suggests that education should take advantage of this intrinsic motivation to learn and to understand. (BD)