Absolute Error Is Not Enough: Ranking Model Performance Without Labels to Estimate Disparities at Scale

Veronica Rammouz, Aaron O. Gonzalez, Carlos Cruzportillo, Adrian Tan, Nicole Lang Beebe, Ke Yang, Anthony Rios


Abstract
Estimating model performance without labeled data is important for deploying NLP systems across diverse domains. Prior work has proposed proxy measures based on distribution shift or predicted correctness, but it remains unclear whether these methods reliably preserve the ranking of domains, which is critical for model selection and risk triage. We study this problem from an ordinal perspective using a two-step framework that pairs a base classifier with an error predictor to estimate instance-level failures and disparities and aggregate them into label-free performance estimates. Across multiple sample sizes from the GeoOLID and Amazon Reviews datasets, large language model–based error predictors substantially outperform drift-based baselines in 𝜌 and 𝜏 rank correlations. We further show that lower absolute estimation error (RMSE) does not necessarily imply better ranking, highlighting the importance of evaluating ordinal consistency directly.

WARNING: This paper contains offensive and hateful speech in the appendix.
Anthology ID:
2026.aacl-long.104
Volume:
Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Yue Zhang, Ruifeng Xu, Ayu Purwarianti, Tong Rong, Jun Suzuki
Venues:
AACL | IJCNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
2290–2307
Language:
URL:
https://aclanthology.org/2026.aacl-long.104/
DOI:
Bibkey:
Cite (ACL):
Veronica Rammouz, Aaron O. Gonzalez, Carlos Cruzportillo, Adrian Tan, Nicole Lang Beebe, Ke Yang, and Anthony Rios. 2026. Absolute Error Is Not Enough: Ranking Model Performance Without Labels to Estimate Disparities at Scale. In Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers), pages 2290–2307, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
Absolute Error Is Not Enough: Ranking Model Performance Without Labels to Estimate Disparities at Scale (Rammouz et al., AACL-IJCNLP 2026)
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PDF:
https://aclanthology.org/2026.aacl-long.104.pdf