The Magic Barrier of Recommender Systems – No Magic, Just Ratings
Presented at the Conference on User Modeling, Adaptation and Personalization, Aalborg, Denmark
Recommender Systems need to deal with different types of users who represent their preferences in various ways. This difference in user behaviour has a deep impact on the ﬁnal performance of the recommender system, where some users may receive either better or worse recommendations depending, mostly, on the quantity and the quality of the information the system knows about the user. Speciﬁcally, the inconsistencies of the user impose a lower bound on the error the system may achieve when predicting ratings for that particular user. In this work, we analyse how the consistency of user ratings (coherence) may predict the performance of recommendation methods. More speciﬁcally, our results show that our deﬁnition of coherence is correlated with the so-called magic barrier of recommender systems, and thus, it could be used to discriminate between easy users (those with a low magic barrier) and difﬁcult ones (those with a high magic barrier). We report experiments where the rating prediction error for the more coherent users is lower than that of the less coherent ones. We further validate these results by using a public dataset, where the magic barrier is not available, in which we obtain similar performance improvements.
|V. Dimitrova , not CWI et al|
|Conference on User Modeling, Adaptation and Personalization|
|Organisation||Human-Centered Data Analytics|
Bellogín Kouki, A, Said, A, & de Vries, A.P. (2014). The Magic Barrier of Recommender Systems – No Magic, Just Ratings. In V Dimitrova & not CWI et al (Eds.), Proceedings of Conference on User Modeling, Adaptation and Personalization 2014 (UMAP 22). Springer. doi:10.1007/978-3-319-08786-3_3