Parameter uncertainties for imperfect surrogate models in the low-noise regime

Fuente: arXiv
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Autores principales: Swinburne, Thomas D, Perez, Danny
Formato: Preprint
Publicado: 2024
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author Swinburne, Thomas D
Perez, Danny
author_facet Swinburne, Thomas D
Perez, Danny
contents Bayesian regression determines model parameters by minimizing the expected loss, an upper bound to the true generalization error. However, the loss ignores misspecification, where models are imperfect. Parameter uncertainties from Bayesian regression are thus significantly underestimated and vanish in the large data limit. This is particularly problematic when building models of low-noise, or near-deterministic, calculations, as the main source of uncertainty is neglected. We analyze the generalization error of misspecified, near-deterministic surrogate models, a regime of broad relevance in science and engineering. We show posterior distributions must cover every training point to avoid a divergent generalization error and design an ansatz that respects this constraint, which for linear models incurs minimal overhead. This is demonstrated on model problems before application to thousand dimensional datasets in atomistic machine learning. Our efficient misspecification-aware scheme gives accurate prediction and bounding of test errors where existing schemes fail, allowing this important source of uncertainty to be incorporated in computational workflows.
format Preprint
id arxiv_https___arxiv_org_abs_2402_01810
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Parameter uncertainties for imperfect surrogate models in the low-noise regime
Swinburne, Thomas D
Perez, Danny
Machine Learning
Data Analysis, Statistics and Probability
Bayesian regression determines model parameters by minimizing the expected loss, an upper bound to the true generalization error. However, the loss ignores misspecification, where models are imperfect. Parameter uncertainties from Bayesian regression are thus significantly underestimated and vanish in the large data limit. This is particularly problematic when building models of low-noise, or near-deterministic, calculations, as the main source of uncertainty is neglected. We analyze the generalization error of misspecified, near-deterministic surrogate models, a regime of broad relevance in science and engineering. We show posterior distributions must cover every training point to avoid a divergent generalization error and design an ansatz that respects this constraint, which for linear models incurs minimal overhead. This is demonstrated on model problems before application to thousand dimensional datasets in atomistic machine learning. Our efficient misspecification-aware scheme gives accurate prediction and bounding of test errors where existing schemes fail, allowing this important source of uncertainty to be incorporated in computational workflows.
title Parameter uncertainties for imperfect surrogate models in the low-noise regime
topic Machine Learning
Data Analysis, Statistics and Probability
url https://arxiv.org/abs/2402.01810