Discovering Collaborative Signals for Next POI Recommendation with Iterative Seq2Graph Augmentation
Discovering Collaborative Signals for Next POI Recommendation with Iterative Seq2Graph Augmentation
Yang Li, Tong Chen, Yadan Luo, Hongzhi Yin, Zi Huang
Proceedings of the Thirtieth International Joint Conference on Artificial Intelligence
Main Track. Pages 1491-1497.
https://doi.org/10.24963/ijcai.2021/206
Being an indispensable component in location-based social networks, next point-of-interest (POI) recommendation recommends users unexplored POIs based on their recent visiting histories. However, existing work mainly models check-in data as isolated POI sequences, neglecting the crucial collaborative signals from cross-sequence check-in information. Furthermore, the sparse POI-POI transitions restrict the ability of a model to learn effective sequential patterns for recommendation. In this paper, we propose Sequence-to-Graph (Seq2Graph) augmentation for each POI sequence, allowing collaborative signals to be propagated from correlated POIs belonging to other sequences. We then devise a novel Sequence-to-Graph POI Recommender (SGRec), which jointly learns POI embeddings and infers a user's temporal preferences from the graph-augmented POI sequence. To overcome the sparsity of POI-level interactions, we further infuse category-awareness into SGRec with a multi-task learning scheme that captures the denser category-wise transitions. As such, SGRec makes full use of the collaborative signals for learning expressive POI representations, and also comprehensively uncovers multi-level sequential patterns for user preference modelling. Extensive experiments on two real-world datasets demonstrate the superiority of SGRec against state-of-the-art methods in next POI recommendation.
Keywords:
Data Mining: Mining Spatial, Temporal Data
Data Mining: Recommender Systems