ACL 2024
HyCoRec: Hypergraph-Enhanced Multi-Preference Learning for Alleviating Matthew Effect in Conversational Recommendation
Yongsen Zheng, Ruilin Xu, Ziliang Chen, Guohua Wang, Mingjie Qian, Jinghui Qin, Liang Lin
ACL 2024

Code: https://github.com/zysensmile/HyCoRec

 

Abstract


The Matthew effect is a notorious issue in Recommender Systems (RSs), i.e., the rich get richer and the poor get poorer, wherein popular items are overexposed while less popular ones are regularly ignored. Most methods examine Matthew effect in static or nearly-static recommendation scenarios. However, the Matthew effect will be increasingly amplified when the user interacts with the system over time. To address these issues, we propose a novel paradigm, Hypergraph-Enhanced Multi-Preference Learning for Alleviating Matthew Effect in Conversational Recommendation (HyCoRec), which aims to alleviate the Matthew effect in conversational recommendation. Concretely, HyCoRec devotes to alleviate the Matthew effect by learning multi-aspect preferences, i.e., item-, entity-, word-, review-, and knowledge-aspect preferences, to effectively generate responses in the conversational task and accurately predict items in the recommendation task when the user chats with the system over time. Extensive experiments conducted on two benchmarks validate that HyCoRec achieves new state-of-the-art performance and the superior of alleviating Matthew effect. Our code is available at https://github.com/zysensmile/HyCoRec.

 

 

Framework


 

 

Experiment


 

 

Conclusion


The Matthew effect is a notorious issue in the CRS, and it will be increasingly amplified due to the dynamic user-system feedback loop. To address these issues, we propose a novel paradigm, HyCoRec, which aims to learn multi-aspect user preferences, i.e., item-, entity-, word-, review-, and knowledge-aspect preferences, to effectively generate diverse responses in the conversation task and accurately predict items in the recommendation task for alleviating Matthew effect. Extensive experiments validate that our HyCoRec outperforms all the compared baselines and the superior of HyCoRec in alleviating Matthew effect in the CRS.

 

 

Limitations


While our HyCoRec has attained a remarkable state-of-the-art performance, it does have certain limitations. Firstly, the complexity and extensive nature of item reviews make the construction of the review-based hypergraph challenging and difficult. Consequently, the current version does not include the review-based hypergraph to capture a wider range of multiplex user relation patterns. Secondly, our proposed method necessitates the design of individual hypergraphs for learning multi-aspect preferences. This limitation could be addressed by developing a general framework that integrate any types of hypergraphs, thereby automatically unifying various knowledge sources.