Consistency and Discrepancy-Based Contrastive Tripartite Graph Learning for Recommendations
Linxin Guo, Yaochen Zhu, Min Gao, Yinghui Tao, Junliang Yu, Chen Chen
TL;DR
This work tackles cold-start challenges in tripartite graph-based recommendations by introducing Consistency and Discrepancy-based graph contrastive learning (CDR). It defines reachable and non-reachable meta-paths to derive high-order consistency and discrepancy metrics, computable via the limit theory of GCN, and uses a contrastive CD loss to supervise embeddings without requiring direct interactions. The model features pre-training and fine-tuning variants (CDR-P and CDR-F) that fuse information from member interactions and tuple interactions, achieving superior performance on group and bundle recommendation tasks across Mafengwo, Youshu, and Last-FM, with notable robustness in extreme cold-start settings. Overall, CDR demonstrates the value of meta-path–driven supervision signals and a contrastive objective for effective tripartite graph learning, advancing practical recommendation systems in sparse data regimes.
Abstract
Tripartite graph-based recommender systems markedly diverge from traditional models by recommending unique combinations such as user groups and item bundles. Despite their effectiveness, these systems exacerbate the longstanding cold-start problem in traditional recommender systems, because any number of user groups or item bundles can be formed among users or items. To address this issue, we introduce a Consistency and Discrepancy-based graph contrastive learning method for tripartite graph-based Recommendation. This approach leverages two novel meta-path-based metrics consistency and discrepancy to capture nuanced, implicit associations between the recommended objects and the recommendees. These metrics, indicative of high-order similarities, can be efficiently calculated with infinite graph convolutional networks layers under a multi-objective optimization framework, using the limit theory of GCN.
