Although there is general consensus concerning the importance and function of interest in our daily lives, there is little agreement about its nature. Four studies of increasing ecological validity (total N = 993) were carried out to compare two different characterizations of interest in terms of the key appraisals involved. The findings indicate that while a two-appraisal model is suitable to explain the interest we can feel towards simple stimuli, a more complex model may better capture the nature of interest in the real world. Further analysis suggested the contrasting previous results could be resolved by arguing that previous models of interest capture different types of interest. This novel finding represents a promising first step towards a more definitive definition of interest, and suggests that while interest may always be related to motivating exploration, learning and general well-being, researchers should be more precise about the type of interest to which they refer.