RichRAG: Crafting Rich Responses for Multi-faceted Queries in Retrieval-Augmented Generation

Shuting Wang, Xin Yu, Mang Wang, Weipeng Chen, Yutao Zhu, Zhicheng Dou


Abstract
Retrieval-augmented generation (RAG) effectively addresses issues of static knowledge and hallucination in large language models. Existing studies mostly focus on question scenarios with clear user intents and concise answers. However, it is prevalent that users issue broad, open-ended queries with diverse sub-intents, for which they desire rich and long-form answers covering multiple relevant aspects. To tackle this important yet underexplored problem, we propose a novel RAG framework, namely RichRAG. It includes a sub-aspect explorer to identify potential sub-aspects of input questions, a multi-faceted retriever to build a candidate pool of diverse external documents related to these sub-aspects, and a generative list-wise ranker, which is a key module to provide the top-k most valuable documents for the final generator. These ranked documents sufficiently cover various query aspects and are aware of the generator’s preferences, hence incentivizing it to produce rich and comprehensive responses for users. The training of our ranker involves a supervised fine-tuning stage to ensure the basic coverage of documents, and a reinforcement learning stage to align downstream LLM’s preferences to the ranking of documents. Experimental results on two publicly available datasets prove that our framework effectively and efficiently provides comprehensive and satisfying responses to users.
Anthology ID:
2025.coling-main.750
Volume:
Proceedings of the 31st International Conference on Computational Linguistics
Month:
January
Year:
2025
Address:
Abu Dhabi, UAE
Editors:
Owen Rambow, Leo Wanner, Marianna Apidianaki, Hend Al-Khalifa, Barbara Di Eugenio, Steven Schockaert
Venue:
COLING
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
11317–11333
Language:
URL:
https://aclanthology.org/2025.coling-main.750/
DOI:
Bibkey:
Cite (ACL):
Shuting Wang, Xin Yu, Mang Wang, Weipeng Chen, Yutao Zhu, and Zhicheng Dou. 2025. RichRAG: Crafting Rich Responses for Multi-faceted Queries in Retrieval-Augmented Generation. In Proceedings of the 31st International Conference on Computational Linguistics, pages 11317–11333, Abu Dhabi, UAE. Association for Computational Linguistics.
Cite (Informal):
RichRAG: Crafting Rich Responses for Multi-faceted Queries in Retrieval-Augmented Generation (Wang et al., COLING 2025)
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PDF:
https://aclanthology.org/2025.coling-main.750.pdf