Computing and Applying Topic-level User Interactions in Microblog Recommendation

With the development of microblog services, tens of thousands of messages are produced every day and recommending useful messages according to users' interest is recognized as an effective way to overcome the information overload problem. Collaborative filtering which rooted from recommender system has been utilized for microblog recommendation, where social relationship information can help improve the recommendation performance. However, most of existing methods only consider the static relationship, i.e. the following relationship, which totally ignore the relationship conveyed by users' repost behaviors. To explore the effects of behavior based relationship on recommendation, we propose an Interaction Based Collaborative Filtering (IBCF) approach. Specifically, we first use topic model to analyze users' interactive behaviors and measure the topic-specific relationship strength, then we incorporate the relationship factor into the matrix factorization framework. Experimental results show that compared to the current popular social recommendation methods, IBCF can achieve better performance on the MAP and NDCG evaluation measures, and have better interpretability for the recommended results.