Multi-view Hypergraph Contrastive Policy Learning for Conversational Recommendation

TL;DR

This paper introduces MHCPL, a multi-view hypergraph contrastive learning model for conversational recommendation systems that captures multiplex user preferences across liking, disliking, and social influence views.

Contribution

The paper proposes a novel multi-view hypergraph contrastive learning approach that models multiplex user preferences and social influence in conversational recommendation.

Findings

Effective modeling of multiplex user preferences.

Improved recommendation accuracy in CRS.

Captures social influence and attribute-based preferences.

Abstract

Conversational recommendation systems (CRS) aim to interactively acquire user preferences and accordingly recommend items to users. Accurately learning the dynamic user preferences is of crucial importance for CRS. Previous works learn the user preferences with pairwise relations from the interactive conversation and item knowledge, while largely ignoring the fact that factors for a relationship in CRS are multiplex. Specifically, the user likes/dislikes the items that satisfy some attributes (Like/Dislike view). Moreover social influence is another important factor that affects user preference towards the item (Social view), while is largely ignored by previous works in CRS. The user preferences from these three views are inherently different but also correlated as a whole. The user preferences from the same views should be more similar than that from different views. The user preferences from Like View should be similar to Social View while different from Dislike View. To this end, we propose a novel model, namely Multi-view Hypergraph Contrastive Policy Learning (MHCPL). Specifically, MHCPL timely chooses useful social information according to the interactive history and builds a dynamic hypergraph with three types of multiplex relations from different views. The multiplex relations in each view are successively connected according to their generation order.