Detecting Hallucinations for Large Language Model-Based Knowledge Graph Reasoning

Xinyan Zhu, Yaoqi Liu, Yue Gao, Huadong Ma, Cheng Yang, Chuan Shi


Abstract
Knowledge graph (KG) reasoning infers new knowledge from existing facts and is widely applied in question answering, recommendation, and decision support. With the rapid development of large language models (LLMs), LLM-based KG reasoning frameworks have become increasingly popular by leveraging retrieved KG information. However, hallucinations in LLMs remain a critical issue. Even when relevant KG knowledge is incorporated, models may still generate incorrect outputs, leading to misinformation and unreliable decisions. Existing hallucination detection methods either focus on LLM internal states or verify consistency with retrieved contexts, but both overlook the structural information in KGs, resulting in suboptimal performance. To address this gap, we propose LUCID, the first halLUcination deteCtIon method for LLM-based knowleDge graph reasoning frameworks. LUCID extracts node and edge features from attention scores and semantic similarities, and integrates them with KG structure using a graph neural network (GNN). Moreover, we also construct manually annotated benchmark datasets for evaluation. Experiments on nine datasets show that LUCID achieves state-of-the-art performance compared to 15 baselines. The code and data are available at: https://github.com/BUPT-GAMMA/LUCID.
Anthology ID:
2026.findings-emnlp.155
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:
3254–3271
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URL:
https://aclanthology.org/2026.findings-emnlp.155/
DOI:
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Cite (ACL):
Xinyan Zhu, Yaoqi Liu, Yue Gao, Huadong Ma, Cheng Yang, and Chuan Shi. 2026. Detecting Hallucinations for Large Language Model-Based Knowledge Graph Reasoning. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 3254–3271, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Detecting Hallucinations for Large Language Model-Based Knowledge Graph Reasoning (Zhu et al., Findings 2026)
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https://aclanthology.org/2026.findings-emnlp.155.pdf