Enhancing Sequential Recommendation with Graph Contrastive Learning
This work addresses the challenge of improving recommendation accuracy for users in sequential recommendation systems, representing an incremental advancement by integrating graph-based global context into existing methods.
The paper tackled the problem of sequential recommendation systems failing to learn appropriate sequence representations by proposing GCL4SR, a framework that uses graph contrastive learning with a weighted item transition graph to incorporate global context and reduce noise, resulting in consistent outperformance over state-of-the-art methods in experiments on real-world datasets.
The sequential recommendation systems capture users' dynamic behavior patterns to predict their next interaction behaviors. Most existing sequential recommendation methods only exploit the local context information of an individual interaction sequence and learn model parameters solely based on the item prediction loss. Thus, they usually fail to learn appropriate sequence representations. This paper proposes a novel recommendation framework, namely Graph Contrastive Learning for Sequential Recommendation (GCL4SR). Specifically, GCL4SR employs a Weighted Item Transition Graph (WITG), built based on interaction sequences of all users, to provide global context information for each interaction and weaken the noise information in the sequence data. Moreover, GCL4SR uses subgraphs of WITG to augment the representation of each interaction sequence. Two auxiliary learning objectives have also been proposed to maximize the consistency between augmented representations induced by the same interaction sequence on WITG, and minimize the difference between the representations augmented by the global context on WITG and the local representation of the original sequence. Extensive experiments on real-world datasets demonstrate that GCL4SR consistently outperforms state-of-the-art sequential recommendation methods.