Contrastive Representation for Interactive Recommendation

TL;DR

This paper introduces CRIR, a contrastive learning approach that enhances feature extraction and sample efficiency in deep reinforcement learning-based interactive recommendation systems.

Contribution

CRIR employs contrastive learning to improve feature quality and sample efficiency in DRL-based IR, addressing current training challenges.

Findings

CRIR significantly improves sample efficiency in DRL IR agents.

CRIR enhances the quality of user preference representations.

Experimental results show superior performance over existing methods.

Abstract

Interactive Recommendation (IR) has gained significant attention recently for its capability to quickly capture dynamic interest and optimize both short and long term objectives. IR agents are typically implemented through Deep Reinforcement Learning (DRL), because DRL is inherently compatible with the dynamic nature of IR. However, DRL is currently not perfect for IR. Due to the large action space and sample inefficiency problem, training DRL recommender agents is challenging. The key point is that useful features cannot be extracted as high-quality representations for the recommender agent to optimize its policy. To tackle this problem, we propose Contrastive Representation for Interactive Recommendation (CRIR). CRIR efficiently extracts latent, high-level preference ranking features from explicit interaction, and leverages the features to enhance users' representation. Specifically, the CRIR provides representation through one representation network, and refines it through our proposed Preference Ranking Contrastive Learning (PRCL). The key insight of PRCL is that it can perform contrastive learning without relying on computations involving high-level representations or large potential action sets. Furthermore, we also propose a data exploiting mechanism and an agent training mechanism to better adapt CRIR to the DRL backbone. Extensive experiments have been carried out to show our method's superior improvement on the sample efficiency while training an DRL-based IR agent.