Subsampled Ensemble Can Improve Generalization Tail Exponentially

Fuente: arXiv
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Autori principali: Qian, Huajie, Ying, Donghao, Lam, Henry, Yin, Wotao
Natura: Preprint
Pubblicazione: 2024
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author Qian, Huajie
Ying, Donghao
Lam, Henry
Yin, Wotao
author_facet Qian, Huajie
Ying, Donghao
Lam, Henry
Yin, Wotao
contents Ensemble learning is a popular technique to improve the accuracy of machine learning models. It traditionally hinges on the rationale that aggregating multiple weak models can lead to better models with lower variance and hence higher stability, especially for discontinuous base learners. In this paper, we provide a new perspective on ensembling. By selecting the most frequently generated model from the base learner when repeatedly applied to subsamples, we can attain exponentially decaying tails for the excess risk, even if the base learner suffers from slow (i.e., polynomial) decay rates. This tail enhancement power of ensembling applies to base learners that have reasonable predictive power to begin with and is stronger than variance reduction in the sense of exhibiting rate improvement. We demonstrate how our ensemble methods can substantially improve out-of-sample performances in a range of numerical examples involving heavy-tailed data or intrinsically slow rates.
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id arxiv_https___arxiv_org_abs_2405_14741
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Subsampled Ensemble Can Improve Generalization Tail Exponentially
Qian, Huajie
Ying, Donghao
Lam, Henry
Yin, Wotao
Optimization and Control
Machine Learning
Ensemble learning is a popular technique to improve the accuracy of machine learning models. It traditionally hinges on the rationale that aggregating multiple weak models can lead to better models with lower variance and hence higher stability, especially for discontinuous base learners. In this paper, we provide a new perspective on ensembling. By selecting the most frequently generated model from the base learner when repeatedly applied to subsamples, we can attain exponentially decaying tails for the excess risk, even if the base learner suffers from slow (i.e., polynomial) decay rates. This tail enhancement power of ensembling applies to base learners that have reasonable predictive power to begin with and is stronger than variance reduction in the sense of exhibiting rate improvement. We demonstrate how our ensemble methods can substantially improve out-of-sample performances in a range of numerical examples involving heavy-tailed data or intrinsically slow rates.
title Subsampled Ensemble Can Improve Generalization Tail Exponentially
topic Optimization and Control
Machine Learning
url https://arxiv.org/abs/2405.14741