ChatRetriever: Adapting Large Language Models for Generalized and Robust Conversational Dense Retrieval

Kelong Mao, Chenlong Deng, Haonan Chen, Fengran Mo, Zheng Liu, Tetsuya Sakai, Zhicheng Dou


Abstract
Conversational search requires accurate interpretation of user intent from complex multi-turn contexts. This paper presents ChatRetriever, which inherits the strong generalization capability of large language models to robustly represent complex conversational sessions for dense retrieval. To achieve this, we propose a simple and effective dual-learning approach that adapts LLM for retrieval via contrastive learning while enhancing the complex session understanding through masked instruction tuning on high-quality conversational instruction tuning data. Extensive experiments on five conversational search benchmarks demonstrate that ChatRetriever significantly outperforms existing conversational dense retrievers, achieving state-of-the-art performance on par with LLM-based rewriting approaches. Furthermore, ChatRetriever exhibits superior robustness in handling diverse conversational contexts. Our work highlights the potential of adapting LLMs for retrieval with complex inputs like conversational search sessions and proposes an effective approach to advance this research direction.
Anthology ID:
2024.emnlp-main.71
Volume:
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2024
Address:
Miami, Florida, USA
Editors:
Yaser Al-Onaizan, Mohit Bansal, Yun-Nung Chen
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1227–1240
Language:
URL:
https://aclanthology.org/2024.emnlp-main.71
DOI:
10.18653/v1/2024.emnlp-main.71
Bibkey:
Cite (ACL):
Kelong Mao, Chenlong Deng, Haonan Chen, Fengran Mo, Zheng Liu, Tetsuya Sakai, and Zhicheng Dou. 2024. ChatRetriever: Adapting Large Language Models for Generalized and Robust Conversational Dense Retrieval. In Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing, pages 1227–1240, Miami, Florida, USA. Association for Computational Linguistics.
Cite (Informal):
ChatRetriever: Adapting Large Language Models for Generalized and Robust Conversational Dense Retrieval (Mao et al., EMNLP 2024)
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PDF:
https://aclanthology.org/2024.emnlp-main.71.pdf