Confident Rankings with Fewer Items: Adaptive LLM Evaluation with Continuous Scores

Esma Balkir, Alice Pernthaller, Marco Basaldella, Jose Hernandez-Orallo, Nigel Collier


Abstract
Computerized Adaptive Testing (CAT) has proven effective for efficient LLM evaluation on multiple-choice benchmarks, but modern LLM evaluation increasingly relies on generation tasks where outputs are scored continuously rather than marked correct/incorrect. We present a principled extension of IRT-based adaptive testing to continuous bounded scores (ROUGE, BLEU, LLM-as-a-Judge) by replacing the Bernoulli response distribution with a heteroskedastic normal distribution. Building on this, we introduce an uncertainty aware ranker with adaptive stopping criteria that achieves reliable model ranking while testing as few items and as cheaply as possible. We validate our method on five benchmarks spanning n-gram-based, embedding-based, and LLM-as-judge metrics. Our method improves ranking correlation by 0.13 𝜏 over random sampling and has 99% accuracy on confident predictions while using 2% of the items after a one-time calibration step
Anthology ID:
2026.emnlp-main.2068
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:
47092–47108
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2068/
DOI:
Bibkey:
Cite (ACL):
Esma Balkir, Alice Pernthaller, Marco Basaldella, Jose Hernandez-Orallo, and Nigel Collier. 2026. Confident Rankings with Fewer Items: Adaptive LLM Evaluation with Continuous Scores. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 47092–47108, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Confident Rankings with Fewer Items: Adaptive LLM Evaluation with Continuous Scores (Balkir et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.2068.pdf