A motivational variable that includes both affective and cognitive as separate but interacting systems. The affective component of interest describes positive emotions accompanying engagement, whereas the cognitive component refers to perceptual and representational activities related to engagement.
Hidi, S., & Renninger, K. A. (2006). The four-phase model of interest development. Educational Psychologist, 41(2), 111-127. doi: 10.1207/s15326985ep4102_4