The major premise of this article is that interest development is critical for students’ motivation and learning. First, we briefly review Svinicki’s (2016) IDEA paper #59, the most recent consideration of motivation and learning in this series. In it, she focused on three motivational theories (expectancy value, goal orientation, and self-determination) and then identified related motivational strategies for classroom use. Following this, we point to differences between these theories and interest development. Whereas students’ consciously formulated beliefs and perspectives are central to the theories reviewed, they are not essential to the conceptualization of interest as a cognitive and motivational variable. We describe characteristics of interest, the Four Phase Model of Interest Development, and implications from research on interest development for motivating students and classroom practice.

Keywords: motivation, interest, expectancy value, goal orientation, interest development, self-determination