Reliability of LLM Judges for Evaluating Entity Alignment

Vaibhava Lakshmi Ravideshik, Mayank Kejriwal


Abstract
Entity Alignment (EA) identifies equivalent entities across knowledge graphs and is critical for knowledge base integration and ontology merging. Evaluating EA systems at scale requires expensive expert annotation, making systematic assessment across diverse domains practically infeasible. LLM-as-judge evaluation offers a potentially scalable alternative, yet its reliability for structured prediction tasks like EA remains unstudied. We present the first systematic benchmarking study across three frontier models, three datasets, and four EA systems, using perturbation bias diagnostics, meta-evaluation across all dataset–judge–prompt combinations, and counterfactual label-flip tests. We identify anchor bias, a failure mode in which judges invert discrimination when the system’s decision label is visible. Label exposure causally collapses judge discrimination (J-ROC-AUC 0.12–0.87), while a label-free protocol recovers near-ceiling capability on distinctive-name datasets (0.93–1.00) and significant recovery on biomedical pairs (0.93–0.95). Counterfactual experiments confirm causality (FSR 53–99%) and reveal a frontier model paradox: stronger judges exhibit greater label sensitivity, not less. A blinded two-annotator human evaluation (102 pairs, Cohen’s κ = 0.902) confirms this mechanism directly. We release the first biomedical EA benchmark (MeSH–SNOMED CT, 15K pairs) and a reproducible auditing framework for LLM judge reliability in EA. Code and data are available at https://github.com/vaibhavalakshmiravideshik/llm-as-a-judge-entity-alignment.
Anthology ID:
2026.emnlp-main.1717
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:
39175–39200
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1717/
DOI:
Bibkey:
Cite (ACL):
Vaibhava Lakshmi Ravideshik and Mayank Kejriwal. 2026. Reliability of LLM Judges for Evaluating Entity Alignment. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 39175–39200, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Reliability of LLM Judges for Evaluating Entity Alignment (Ravideshik & Kejriwal, EMNLP 2026)
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https://aclanthology.org/2026.emnlp-main.1717.pdf