Cited by 85Adversarial Robustness in Machine LearningEthics and Social Impacts of AITopic Modeling

Humans or LLMs as the Judge? A Study on Judgement Bias

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Chen, Guiming Hardy, Chen, Shunian, Liu, Ziche, Jiang, Feng, Wang, Benyou·2024·Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing

Abstract

Adopting human and large language models (LLM) as judges (a.k.a human-and LLM-as-ajudge) for evaluating the performance of LLMs has recently gained attention.Nonetheless, this approach concurrently introduces potential biases from human and LLMs, questioning the reliability of the evaluation results.In this paper, we propose a novel framework that is free from referencing groundtruth annotations for investigating Misinformation Oversight Bias, Gender Bias, Authority Bias and Beauty Bias on LLM and human judges.We curate a dataset referring to the revised Bloom's Taxonomy and conduct thousands of evaluations.Results show that human and LLM judges are vulnerable to perturbations to various degrees, and that even the cutting-edge judges possess considerable biases.We further exploit these biases to conduct attacks on LLM judges.We hope that our work can notify the community of the bias and vulnerability of human-and LLMas-a-judge, as well as the urgency of developing robust evaluation systems 1 .Warning: we provide illustrative attack protocols to reveal the vulnerabilities of LLM judges, aiming to develop more robust ones.

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Crossref · 10.18653/v1/2024.emnlp-main.474

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  • The faithfulness of LLMs in establishing judgment is established in previous works.

    “The faithfulness of LLMs in establishing judgment is established in previous works33–35.”

    From AgentClinic: a multimodal benchmark for tool-using clinical AI agents (2026) · cites this paper as [35]

    The Abstract (page unavailable) says LLM judges have biases that question the reliability of their evaluations; it reports that even cutting-edge judges possess considerable biases. Section 2.2 (page unavailable) likewise says their annotation results require validation, rather than treating the faithfulness of their judgments as established. (LLM, conf=0.86)

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  • Although the 3-vote majority consensus protocol reduces stochastic fluctuation, the judge model may exhibit systematic biases toward responses generated by models in the same model family, and may be more lenient on verbose near-misses than a human annotator would be.

    “Although the 3-vote majority consensus protocol reduces stochastic fluctuation, the judge model may exhibit systematic biases toward responses generated by models in the same model family (Zheng et al., 2023;Ye et al., 2024), and may be more lenient on verbose near-misses than a human annotator would be (Zheng et al., 2023;Ye et al., 2024;Chen et al., 2024).”

    From Beyond the Context Window: A Cost-Performance Analysis of Fact-Based Memory vs. Long-Context LLMs for Persistent Agents (2026) · cites this paper as Chen et al., 2024

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  • Chen et al. (2024) shows that some biases are present in both LLM judges and human evaluators.

    “Chen et al. (2024) shows that some of these biases are not only present in LLM judges, but also often in human evaluators.”

    From Know Thy Judge: On the Robustness Meta-Evaluation of LLM Safety Judges (2025) · cites this paper as Chen et al., 2024

  • Length bias is a known issue of evaluations that rely on model-based graders.

    “Length bias is a known issue of evaluations that rely on model-based graders (Ye et al., 2024; Chen et al., 2024).”

    From HealthBench: Evaluating Large Language Models Towards Improved Human Health (2025) · cites this paper as Chen et al., 2024

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Research works printed but not linked: 7

  1. Elizabeth Clark, Tal August, Sofia Serrano, Nikita Haduong, Suchin Gururangan, and Noah A Smith. 2021. All that's' human'is not gold: Evaluating hu- man evaluation of generated text. arXiv preprint arXiv:2107.00061. · arXiv
  2. Michael J. Keough Gerry P. Quinn. 2002. Experimental Design and Data Analysis for Biologists, 1 edition. Cambridge University Press.
  3. Perttu Hämäläinen, Mikke Tavast, and Anton Kunnari. 2023. Evaluating large language models in gener- ating synthetic hci research data: a case study. In Proceedings of the 2023 CHI Conference on Human Factors in Computing Systems, pages 1-19.
  4. David M Howcroft, Anya Belz, Miruna Clinciu, Dimitra Gkatzia, Sadid A Hasan, Saad Mahamood, Simon Mille, Emiel Van Miltenburg, Sashank Santhanam, and Verena Rieser. 2020. Twenty years of confusion in human evaluation: Nlg needs evaluation sheets and standardised definitions. In 13th International Conference on Natural Language Generation 2020, pages 169-182. Association for Computational Lin- guistics.
  5. Yuzhen Huang, Yuzhuo Bai, Zhihao Zhu, Junlei Zhang, Jinghan Zhang, Tangjun Su, Junteng Liu, Chuancheng Lv, Yikai Zhang, Jiayi Lei, Yao Fu, Maosong Sun, and Junxian He. 2023. C-eval: A multi-level multi-discipline chinese evaluation suite for foundation models. In Advances in Neural Infor- mation Processing Systems.
  6. Kelly Weidner, Frederik Beuk, and Anjali Bal. 2020. Fake news and the willingness to share: a schemer schema and confirmatory bias perspective. Journal of Product & Brand Management, 29(2):180-187.
  7. Wangchunshu Zhou and Ke Xu. 2020. Learning to compare for better training and evaluation of open domain natural language generation models. In Pro- ceedings of the 34th AAAI Conference on Artificial Intelligence, pages 9717-9724.

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Authors
Chen, G. H., Chen, S., Liu, Z., Jiang, F., & Wang, B.
Affiliations
Shenzhen Research Institute of Big Data (CN)
Venue
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Published
2024
Pages
8301-8327
OpenAlex
W4404782878
Cited by
76
References
0
Citations by year
2026: 48 · 2025: 25 · 2024: 3
FWCI
21.94
Type
conference paper
Language
en
Open access
Licence
cc-by
Locations
Conference on Empirical Methods in Natural Language Processing (EMNLP) (publishedVersion, cc-by)
Funders
National Natural Science Foundation of China (12326608)
Topics
  • Physical Sciences › Computer Science › Artificial Intelligence › Adversarial Robustness in Machine Learning
  • Social Sciences › Safety Research › Ethics and Social Impacts of AI
  • Physical Sciences › Computer Science › Artificial Intelligence › Topic Modeling
Keywords
LLM-as-a-judge, LLM evaluation, judgment bias, gender bias, authority bias, beauty bias, Bloom's taxonomy, evaluation robustness

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