Towards Effective Structured Context Modeling for Conversational Recommender Systems via Dual-node Monte Carlo Tree Search

Jincheng Zhang, Chen Huang, Wenqiang Lei, See-Kiong Ng, Yang Deng


Abstract
We investigate the role of conversational context modeling in user preference tracking for Conversational Recommendation Systems (CRSs). In this regard, we propose DREAMS, a novel tree-structured context modeling framework that explicitly captures user preference evolution throughout multi-turn interactions. DREAMS introduces two specialized node types to support the two fundamental objectives of CRSs: preference elicitation and preference exploitation. Specifically, elicitation nodes leverage Monte Carlo Tree Search (MCTS) to strategically explore conversational actions and infer latent user preferences, while exploitation nodes employ LLM-based refinement to transform the tracked preference state into structured retrieval queries for recommendation. Extensive experiments on benchmark datasets demonstrate the effectiveness of DREAMS and its design.
Anthology ID:
2026.emnlp-main.1257
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
28635–28659
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1257/
DOI:
Bibkey:
Cite (ACL):
Jincheng Zhang, Chen Huang, Wenqiang Lei, See-Kiong Ng, and Yang Deng. 2026. Towards Effective Structured Context Modeling for Conversational Recommender Systems via Dual-node Monte Carlo Tree Search. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 28635–28659, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Towards Effective Structured Context Modeling for Conversational Recommender Systems via Dual-node Monte Carlo Tree Search (Zhang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1257.pdf