Central to self-determination theory (SDT) is the notion that autonomously motivated learning relates to greater learning benefits. While learners' intrinsic motivation has received substantial attention, learners also display volitional learning when they come to endorse the personal meaning or self-relevance of the learning task. In Part I of this review, we discuss how the process of internalization, in addition to intrinsic motivation, constitutes an important growth process. In Part II, we indicate how autonomy-supportive teaching and the provision of a rationale are critical to fostering internalization, and we review past empirical studies. Further, we propose an emerging model to explain when provided rationales foster perceived self-relevance and promote the process of internalization, thereby, considering both critical features of the rationale itself and the broader context in which the rationale becomes embedded. In Part III, the process of internalization is discussed in relation to the concepts of utility value and instrumentality.