titleCalibration as a First-Class Criterion in LLM Evaluation
authorsMario Sanz-Guerrero, Katharina von der Wense
date2026-09-22
venuearXiv (preprint, not peer reviewed)
idarXiv:2609.26489
upvotes4 (Hugging Face Daily Papers, 2026-11-01)
linksabs pdf hf
abstractCalibration of language models -- the alignment between expressed or implicit confidence and empirical correctness -- is a well-studied subfield within NLP. Methods to measure it already exist. The problem is adoption: outside this subfield, NLP research regularly introduces new models, datasets, and benchmarks without checking whether the model's confidence scores are meaningful. We argue that this adoption gap is a major obstacle to trustworthy LLM evaluation. Miscalibration causes problems in two distinct areas: at deployment, where overconfident mistakes cause real harm, and inside the research pipeline, where methods like LLM-as-a-judge, synthetic data generation, and active learning rely on calibrated confidence without verifying it. Standard calibration metrics only require two inputs per example: a confidence score and a correctness judgment. Most benchmarks in use today already provide both, meaning calibration can be reported immediately. For open-ended generation, however, defining these two inputs is still an open challenge. We argue that each NLP subfield should pair its main performance metric with a calibration score and call for treating calibration as an essential property of every model rather than a niche topic.

cite

@misc{sanzguerrero2026calibration,
  title={Calibration as a First-Class Criterion in LLM Evaluation},
  author={Mario Sanz-Guerrero and Katharina von der Wense},
  year={2026},
  eprint={2609.26489},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2609.26489}
}