Factored heterogeneous similarity model for recommendation with implicit feedback.

• We study an important problem, i.e., recommendation with implicit feedback. • We propose a heterogeneous similarity to capture rich correlations. • We design a novel and flexible recommendation algorithm, i.e., Poi-FHSM. • We conduct extensive empirical studies on five real-world datasets. Recommendation with implicit feedback such as "bought" in e-commerce sites and "like" in online-to-offline services is an important problem because of the abundance of users' online behaviors. Previous works for modeling users' implicit feedback mainly focus on designing some predefined similarity, learned similarity, or hybrid similarity between two users (or two items). However, these similarities either can not capture both the local and global relations among users (or items) simultaneously, or they are not easy to be tuned due to the tradeoff parameter in the linear hybridization. Moreover, information from one single group, either a user group or an item group, may not be sufficient for modeling users' preferences well. To this end, in this paper, we first propose a heterogeneous similarity to capture rich correlations among users and items via a concise integration, and then design a novel recommendation algorithm, i.e., pointwise factored heterogeneous similarity model (Poi-FHSM), in which we fully exploit the proposed similarity in a flexible pointwise preference learning paradigm. Finally, we conduct extensive empirical studies on five real-world datasets, and find that our Poi-FHSM performs better than those based on the predefined, learned and hybrid similarity, as well as the state-of-the-art deep learning-based methods, showcasing the effectiveness of our heterogeneous similarity and recommendation algorithm. [ABSTRACT FROM AUTHOR]