Tree-like Interaction Learning for Bundle Recommendation

Bundle recommendation suggests a set of items to users against their complex needs, where user-bundle interaction learning is key. It is observed that Gromov's $\delta$-hyperbolicity of the interaction graph in bundle recommendation is smaller (lower is more hyperbolic) than those in traditional item recommendation when measuring a graph's tree likeness. However, state-of-the-art bundle recommendation methods learn to embed the entities (user, bundle, item) of tree-like interaction graph in Euclidean space, which could cause severe distortion problems. We argue hyperbolic space provides a promising way to get accurate entity embeddings, with this paper proposing a novel bundle recommendation model. The model learns user preferences via hyperbolic graph convolution, aiming at decreasing the distortion of bundle graph node embeddings. Extensive empirical experiments conducted on two real-world datasets confirm that our model achieves promising performance compared to baseline methods representing state-of-the-art bundle recommendation methods.