The role of preference consistency, defaults and musical expertise in users' exploration behavior in a genre exploration recommender

Recommender systems are efficient at predicting users' current preferences, but how users' preferences develop over time is still under-explored. In this work, we study the development of users' musical preferences. Exploring musical preference consistency between short-term and long-term preferences in data from earlier studies, we find that users with higher musical expertise have more consistent preferences at their top-listened artists and tags than those with lower musical expertise. Users typically chose to explore genres that were close to their current preferences, and this effect was stronger for expert users. Based on these findings we conducted a user study on genre exploration to investigate (1) whether it is possible to nudge users to explore more distant genres, and (2) how users' exploration behaviors within a genre are influenced by default recommendation settings that balance personalization with genre representativeness in different ways. Our results show that users were more likely to select the more distant genres if these were presented at the top of the list. However, users with high musical expertise were less likely to do so, consistent with our earlier findings. When given a representative or mixed (balanced) default for exploration within a genre, users selected less personalized recommendation settings and explored further away from their current preferences, than with a personalized default. However, this effect was moderated by users' slider usage behaviors. Overall, our results suggest that (personalized) defaults can nudge users to explore new, more distant genres and songs. However, the effect is smaller for those with higher musical expertise levels.