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Are Hallucinations Bad Estimations?

Machine Learning 2025-09-29 v1 Artificial Intelligence Computation and Language Computer Vision and Pattern Recognition Machine Learning

Abstract

We formalize hallucinations in generative models as failures to link an estimate to any plausible cause. Under this interpretation, we show that even loss-minimizing optimal estimators still hallucinate. We confirm this with a general high probability lower bound on hallucinate rate for generic data distributions. This reframes hallucination as structural misalignment between loss minimization and human-acceptable outputs, and hence estimation errors induced by miscalibration. Experiments on coin aggregation, open-ended QA, and text-to-image support our theory.

Keywords

Cite

@article{arxiv.2509.21473,
  title  = {Are Hallucinations Bad Estimations?},
  author = {Hude Liu and Jerry Yao-Chieh Hu and Jennifer Yuntong Zhang and Zhao Song and Han Liu},
  journal= {arXiv preprint arXiv:2509.21473},
  year   = {2025}
}

Comments

Code is available at https://github.com/MAGICS-LAB/hallucination

R2 v1 2026-07-01T05:56:54.670Z