Concise and Sufficient Sub-Sentence Citations for Retrieval-Augmented Generation

Guo Chen, Qiuyuan Li, Qiuxian Li, Hongliang Dai, Xiang Chen, Piji Li


Abstract
In retrieval-augmented generation (RAG) question answering systems, generating citations for large language model (LLM) outputs enhances verifiability and helps users identify potential hallucinations. Existing citation generation methods for retrieval-augmented generation usually provide evidence at the paragraph or sentence level. Although such citations improve verifiability, they may still impose unnecessary reading burden on users: a cited sentence can contain irrelevant clauses, while an answer-bearing clause may lack sufficient contextual information such as the referred subject. In this paper, we study concise and sufficient sub-sentence citation generation, aiming to identify minimal yet self-contained evidence spans for answer verification. To this end, we first develop annotation guidelines for such citations and construct a corresponding dataset. To reduce annotation cost, we propose a data augmentation framework that generates synthetic citation annotations and filters low-quality instances using an evaluator model. Our experiments on the constructed dataset demonstrate that the proposed approach can generate high-quality and more readable citations. The code and data will be publicly released.
Anthology ID:
2026.emnlp-main.1082
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:
24853–24868
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1082/
DOI:
Bibkey:
Cite (ACL):
Guo Chen, Qiuyuan Li, Qiuxian Li, Hongliang Dai, Xiang Chen, and Piji Li. 2026. Concise and Sufficient Sub-Sentence Citations for Retrieval-Augmented Generation. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 24853–24868, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Concise and Sufficient Sub-Sentence Citations for Retrieval-Augmented Generation (Chen et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1082.pdf