LLMs instead of Human Judges? A Large Scale Empirical Study across 20 NLP Evaluation Tasks
Anna Bavaresco, Raffaella Bernardi, Leonardo Bertolazzi, Desmond Elliott, Raquel Fernández, Albert Gatt, Esam Ghaleb, Mario Giulianelli
Abstract
There is an increasing trend towards evaluating NLP models with LLMs instead of human judgments, raising questions about the validity of these evaluations, as well as their reproducibility in the case of proprietary models. We provide JUDGE-BENCH, an extensible collection of 20 NLP datasets with human annotations covering a broad range of evaluated properties and types of data, and comprehensively evaluate 11 current LLMs, covering both open-weight and proprietary models, for their ability to replicate the annotations. Our evaluations show substantial variance across models and datasets. Models are reliable evaluators on some tasks, but overall display substantial variability depending on the property being evaluated, the expertise level of the human judges, and whether the language is human or model-generated. We conclude that LLMs should be carefully validated against human judgments before being used as evaluators.
BibTeX
@inproceedings{bavaresco-etal-2025-llms,
title = "{LLM}s instead of Human Judges? A Large Scale Empirical Study across 20 {NLP} Evaluation Tasks",
author = "Bavaresco, Anna and
Bernardi, Raffaella and
Bertolazzi, Leonardo and
Elliott, Desmond and
Fern{\'a}ndez, Raquel and
Gatt, Albert and
Ghaleb, Esam and
Giulianelli, Mario and
Hanna, Michael and
Koller, Alexander and
Martins, Andre and
Mondorf, Philipp and
Neplenbroek, Vera and
Pezzelle, Sandro and
Plank, Barbara and
Schlangen, David and
Suglia, Alessandro and
Surikuchi, Aditya K and
Takmaz, Ece and
Testoni, Alberto",
editor = "Che, Wanxiang and
Nabende, Joyce and
Shutova, Ekaterina and
Pilehvar, Mohammad Taher",
booktitle = "Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)",
month = jul,
year = "2025",
address = "Vienna, Austria",
publisher = "Association for Computational Linguistics",
url = "https://aclanthology.org/2025.acl-short.20/",
doi = "10.18653/v1/2025.acl-short.20",
pages = "238--255",
ISBN = "979-8-89176-252-7"
}