Discrete Listwise Personalized Ranking for Fast Top-N Recommendation with Implicit Feedback

Discrete Listwise Personalized Ranking for Fast Top-N Recommendation with Implicit Feedback

Fangyuan Luo, Jun Wu, Tao Wang

Proceedings of the Thirty-First International Joint Conference on Artificial Intelligence
Main Track. Pages 2159-2165. https://doi.org/10.24963/ijcai.2022/300

We address the efficiency problem of personalized ranking from implicit feedback by hashing users and items with binary codes, so that top-N recommendation can be fast executed in a Hamming space by bit operations. However, current hashing methods for top-N recommendation fail to align their learning objectives (such as pointwise or pairwise loss) with the benchmark metrics for ranking quality (e.g. Average Precision, AP), resulting in sub-optimal accuracy. To this end, we propose a Discrete Listwise Personalized Ranking (DLPR) model that optimizes AP under discrete constraints for fast and accurate top-N recommendation. To resolve the challenging DLPR problem, we devise an efficient algorithm that can directly learn binary codes in a relaxed continuous solution space. Specifically, theoretical analysis shows that the optimal solution to the relaxed continuous optimization problem is exactly the same as that of the original discrete DLPR problem. Through extensive experiments on two real-world datasets, we show that DLPR consistently surpasses state-of-the-art hashing methods for top-N recommendation.
Keywords:
Data Mining: Recommender Systems