Refining Text Generation for Realistic Conversational Recommendation via Direct Preference Optimization

Manato Tajiri, Michimasa Inaba


Abstract
Conversational Recommender Systems (CRSs) aim to elicit user preferences via natural dialogue to provide suitable item recommendations. However, current CRSs often deviate from realistic human interactions by rapidly recommending items in brief sessions. This work addresses this gap by leveraging Large Language Models (LLMs) to generate dialogue summaries from dialogue history and item recommendation information from item description. This approach enables the extraction of both explicit user statements and implicit preferences inferred from the dialogue context. We introduce a method using Direct Preference Optimization (DPO) to ensure dialogue summary and item recommendation information are rich in information crucial for effective recommendations. Experiments on two public datasets validate our method’s effectiveness in fostering more natural and realistic conversational recommendation processes. Our implementation is publicly available at: https://github.com/UEC-InabaLab/Refining-LLM-Text
Anthology ID:
2025.emnlp-main.1456
Volume:
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
EMNLP
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Publisher:
Association for Computational Linguistics
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Pages:
28628–28649
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URL:
https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.1456/
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Cite (ACL):
Manato Tajiri and Michimasa Inaba. 2025. Refining Text Generation for Realistic Conversational Recommendation via Direct Preference Optimization. In Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing, pages 28628–28649, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
Refining Text Generation for Realistic Conversational Recommendation via Direct Preference Optimization (Tajiri & Inaba, EMNLP 2025)
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