CAFE: Coarse-to-Fine Neural Symbolic Reasoning for Explainable Recommendation
This addresses the problem of explainable recommendation for e-commerce users by providing a more effective and interpretable method, though it is incremental as it builds on existing knowledge graph reasoning approaches.
The paper tackles the challenge of incorporating knowledge graphs into e-commerce recommender systems to improve performance and generate explanations by proposing CAFE, a coarse-to-fine neural symbolic reasoning approach that first creates user profiles to guide path-finding, resulting in substantial gains in recommendation performance on four real-world benchmarks.
Recent research explores incorporating knowledge graphs (KG) into e-commerce recommender systems, not only to achieve better recommendation performance, but more importantly to generate explanations of why particular decisions are made. This can be achieved by explicit KG reasoning, where a model starts from a user node, sequentially determines the next step, and walks towards an item node of potential interest to the user. However, this is challenging due to the huge search space, unknown destination, and sparse signals over the KG, so informative and effective guidance is needed to achieve a satisfactory recommendation quality. To this end, we propose a CoArse-to-FinE neural symbolic reasoning approach (CAFE). It first generates user profiles as coarse sketches of user behaviors, which subsequently guide a path-finding process to derive reasoning paths for recommendations as fine-grained predictions. User profiles can capture prominent user behaviors from the history, and provide valuable signals about which kinds of path patterns are more likely to lead to potential items of interest for the user. To better exploit the user profiles, an improved path-finding algorithm called Profile-guided Path Reasoning (PPR) is also developed, which leverages an inventory of neural symbolic reasoning modules to effectively and efficiently find a batch of paths over a large-scale KG. We extensively experiment on four real-world benchmarks and observe substantial gains in the recommendation performance compared with state-of-the-art methods.