LLM-based Conversational Recommendation Agents with Collaborative Verbalized Experience

Yaochen Zhu, Harald Steck, Dawen Liang, Yinhan He, Nathan Kallus, Jundong Li


Abstract
Large language models (LLMs) have demonstrated impressive zero-shot capabilities in conversational recommender systems (CRS). However, effectively utilizing historical conversations remains a significant challenge. Current approaches either retrieve few-shot examples or extract global rules to enhance the prompt, which fail to capture the implicit and preference-oriented knowledge. To address this challenge, we propose LLM-based Conversational Recommendation Agents with Collaborative Verbalized Experience, abbreviated as CRAVE. CRAVE begins by sampling trajectories of LLM-based CRS agents on historical queries and establishing verbalized experience banks by reflecting the agents’ actions on user feedback. Additionally, we introduce a collaborative retriever network fine-tuned with item content-parameterized multinomial likelihood on query-item pairs to retrieve preference-oriented verbal experiences for new queries. Furthermore, we developed a debater-critic agent (DCA) system where each agent maintains an independent collaborative experience bank and works together to enhance the CRS recommendations. We demonstrate that the open-ended debate and critique nature of DCA benefits significantly from the collaborative experience augmentation with CRAVE. The code is available at https://github.com/yaochenzhu/CRAVE.
Anthology ID:
2025.findings-emnlp.119
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2025
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
2207–2220
Language:
URL:
https://preview.aclanthology.org/author-page-yu-wang-polytechnic/2025.findings-emnlp.119/
DOI:
10.18653/v1/2025.findings-emnlp.119
Bibkey:
Cite (ACL):
Yaochen Zhu, Harald Steck, Dawen Liang, Yinhan He, Nathan Kallus, and Jundong Li. 2025. LLM-based Conversational Recommendation Agents with Collaborative Verbalized Experience. In Findings of the Association for Computational Linguistics: EMNLP 2025, pages 2207–2220, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
LLM-based Conversational Recommendation Agents with Collaborative Verbalized Experience (Zhu et al., Findings 2025)
Copy Citation:
PDF:
https://preview.aclanthology.org/author-page-yu-wang-polytechnic/2025.findings-emnlp.119.pdf
Checklist:
 2025.findings-emnlp.119.checklist.pdf