HutCRS: Hierarchical User-Interest Tracking for Conversational Recommender System

Mingjie Qian, Yongsen Zheng, Jinghui Qin, Liang Lin


Abstract
Conversational Recommender System (CRS) aims to explicitly acquire user preferences towards items and attributes through natural language conversations. However, existing CRS methods ask users to provide explicit answers (yes/no) for each attribute they require, regardless of users’ knowledge or interest, which may significantly reduce the user experience and semantic consistency. Furthermore, these methods assume that users like all attributes of the target item and dislike those unrelated to it, which can introduce bias in attribute-level feedback and impede the system’s ability to accurately identify the target item. To address these issues, we propose a more realistic, user-friendly, and explainable CRS framework called Hierarchical User-Interest Tracking for Conversational Recommender System (HutCRS). HutCRS portrays the conversation as a hierarchical interest tree that consists of two stages. In stage I, the system identifies the aspects that the user prefers while the system asks about attributes related to these positive aspects or recommends items in stage II. In addition, we develop a Hierarchical-Interest Policy Learning (HIPL) module to integrate the decision-making process of which aspects to ask and when to ask about attributes or recommend items. Moreover, we classify the attribute-level feedback results to further enhance the system’s ability to capture special information, such as attribute instances that are accepted by users but not presented in their historical interactive data. Extensive experiments on four benchmark datasets demonstrate the superiority of our method. The implementation of HutCRS is publicly available at https://github.com/xinle1129/HutCRS.
Anthology ID:
2023.emnlp-main.635
Volume:
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing
Month:
December
Year:
2023
Address:
Singapore
Editors:
Houda Bouamor, Juan Pino, Kalika Bali
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
10281–10290
Language:
URL:
https://aclanthology.org/2023.emnlp-main.635
DOI:
10.18653/v1/2023.emnlp-main.635
Bibkey:
Cite (ACL):
Mingjie Qian, Yongsen Zheng, Jinghui Qin, and Liang Lin. 2023. HutCRS: Hierarchical User-Interest Tracking for Conversational Recommender System. In Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing, pages 10281–10290, Singapore. Association for Computational Linguistics.
Cite (Informal):
HutCRS: Hierarchical User-Interest Tracking for Conversational Recommender System (Qian et al., EMNLP 2023)
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PDF:
https://aclanthology.org/2023.emnlp-main.635.pdf
Video:
 https://aclanthology.org/2023.emnlp-main.635.mp4