Local collaborative ranking

J Lee, S Bengio, S Kim, G Lebanon… - Proceedings of the 23rd …, 2014 - dl.acm.org
Proceedings of the 23rd international conference on World wide web, 2014dl.acm.org
Personalized recommendation systems are used in a wide variety of applications such as
electronic commerce, social networks, web search, and more. Collaborative filtering
approaches to recommendation systems typically assume that the rating matrix (eg, movie
ratings by viewers) is low-rank. In this paper, we examine an alternative approach in which
the rating matrix is locally low-rank. Concretely, we assume that the rating matrix is low-rank
within certain neighborhoods of the metric space defined by (user, item) pairs. We combine …
Personalized recommendation systems are used in a wide variety of applications such as electronic commerce, social networks, web search, and more. Collaborative filtering approaches to recommendation systems typically assume that the rating matrix (e.g., movie ratings by viewers) is low-rank. In this paper, we examine an alternative approach in which the rating matrix is locally low-rank. Concretely, we assume that the rating matrix is low-rank within certain neighborhoods of the metric space defined by (user, item) pairs. We combine a recent approach for local low-rank approximation based on the Frobenius norm with a general empirical risk minimization for ranking losses. Our experiments indicate that the combination of a mixture of local low-rank matrices each of which was trained to minimize a ranking loss outperforms many of the currently used state-of-the-art recommendation systems. Moreover, our method is easy to parallelize, making it a viable approach for large scale real-world rank-based recommendation systems.
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