Web Search Is Not Enough: LLMs Fail to Account for Paper Retraction Status

Huy Hoang Ha, Benoit Favre, Cyril Labbe, François Portet


Abstract
Large language models (LLMs) learn scientific knowledge from static training corpora, while web search can provide updated information such as paper retractions. This matters for LLM-based literature systems because a model may have seen a paper as valid evidence, while current web results report that it has been retracted. If an LLM does not use the updated retraction status, it may cite a retracted paper as valid evidence. We analyze eleven open-weight models on the retraction-status task and ten on the citation-recommendation task. With web-search results provided, LLMs increase correct status answers for retracted papers from 11.0% to 94.0%. But the same models do not use the retrieved context as reliably when no retraction signal is present or when they recommend citations. On non-retracted papers under web search, models answer “I don’t know” in 52.9% of answers in the retraction-status task. In the citation-recommendation task, even when search results state the retraction and the prompt asks for warnings, models recommend retracted papers without warning in 10.2% of answers. A separate pattern appears for highly cited retractions. Models give fewer correct status answers for high-citation than low-citation retractions (89.3% versus 96.4%). OLMo’s training data suggests one reason. Highly cited retractions appear more often in training data, mostly without any retraction signal, so retrieved retraction information may compete with outdated training knowledge. Overall, access to web search does not guarantee that LLMs will correctly use a paper’s current status when answering questions or producing citations, highlighting the broader challenge of knowledge updating in LLM systems.
Anthology ID:
2026.findings-emnlp.2070
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
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SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
44052–44077
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URL:
https://aclanthology.org/2026.findings-emnlp.2070/
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Cite (ACL):
Huy Hoang Ha, Benoit Favre, Cyril Labbe, and François Portet. 2026. Web Search Is Not Enough: LLMs Fail to Account for Paper Retraction Status. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 44052–44077, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Web Search Is Not Enough: LLMs Fail to Account for Paper Retraction Status (Hoang Ha et al., Findings 2026)
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https://aclanthology.org/2026.findings-emnlp.2070.pdf