On the Role of Citations in Preference Data

Yu Hou, Hal Daumé III, Rachel Rudinger, William Gantt Walden


Abstract
Many NLP tasks require systems to provide attribution in their outputs—i.e. citations to grounding sources. Attribution serves as a bulwark against model hallucination and as a means for users to verify the credibility of model outputs. Yet, it is unclear how humans and LLMs evaluate citations when comparing outputs, a process central to reward modeling and modern LLM post-training. This paper studies the role of citations in the preferences of human judges and four open-source LLMs within the context of scientific question answering, leveraging mixed effects models to investigate the influence of citations on pairwise judgments. Among our key findings are (1) that humans prefer more diverse citations but fewer overall, and (2) that LLMs show some citation-related preferences compared to humans, despite lacking access to the sources, but these preferences depend on the data and specific models. We further discuss the implications of our findings for preference data collection.
Anthology ID:
2026.emnlp-main.1781
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:
40582–40599
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1781/
DOI:
Bibkey:
Cite (ACL):
Yu Hou, Hal Daumé III, Rachel Rudinger, and William Gantt Walden. 2026. On the Role of Citations in Preference Data. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 40582–40599, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
On the Role of Citations in Preference Data (Hou et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1781.pdf