Saved in:
Bibliographic Details
Main Authors: Köbschall, Kirsten, Buschjäger, Sebastian, Fischer, Raphael, Hartung, Lisa, Kramer, Stefan
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2509.18962
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918177084014592
author Köbschall, Kirsten
Buschjäger, Sebastian
Fischer, Raphael
Hartung, Lisa
Kramer, Stefan
author_facet Köbschall, Kirsten
Buschjäger, Sebastian
Fischer, Raphael
Hartung, Lisa
Kramer, Stefan
contents Ensemble methods for stream mining necessitate managing multiple models and updating them as data distributions evolve. Considering the calls for more sustainability, established methods are however not sufficiently considerate of ensemble members' computational expenses and instead overly focus on predictive capabilities. To address these challenges and enable green online learning, we propose heterogeneous online ensembles (HEROS). For every training step, HEROS chooses a subset of models from a pool of models initialized with diverse hyperparameter choices under resource constraints to train. We introduce a Markov decision process to theoretically capture the trade-offs between predictive performance and sustainability constraints. Based on this framework, we present different policies for choosing which models to train on incoming data. Most notably, we propose the novel $ζ$-policy, which focuses on training near-optimal models at reduced costs. Using a stochastic model, we theoretically prove that our $ζ$-policy achieves near optimal performance while using fewer resources compared to the best performing policy. In our experiments across 11 benchmark datasets, we find empiric evidence that our $ζ$-policy is a strong contribution to the state-of-the-art, demonstrating highly accurate performance, in some cases even outperforming competitors, and simultaneously being much more resource-friendly.
format Preprint
id arxiv_https___arxiv_org_abs_2509_18962
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Lift What You Can: Green Online Learning with Heterogeneous Ensembles
Köbschall, Kirsten
Buschjäger, Sebastian
Fischer, Raphael
Hartung, Lisa
Kramer, Stefan
Machine Learning
Ensemble methods for stream mining necessitate managing multiple models and updating them as data distributions evolve. Considering the calls for more sustainability, established methods are however not sufficiently considerate of ensemble members' computational expenses and instead overly focus on predictive capabilities. To address these challenges and enable green online learning, we propose heterogeneous online ensembles (HEROS). For every training step, HEROS chooses a subset of models from a pool of models initialized with diverse hyperparameter choices under resource constraints to train. We introduce a Markov decision process to theoretically capture the trade-offs between predictive performance and sustainability constraints. Based on this framework, we present different policies for choosing which models to train on incoming data. Most notably, we propose the novel $ζ$-policy, which focuses on training near-optimal models at reduced costs. Using a stochastic model, we theoretically prove that our $ζ$-policy achieves near optimal performance while using fewer resources compared to the best performing policy. In our experiments across 11 benchmark datasets, we find empiric evidence that our $ζ$-policy is a strong contribution to the state-of-the-art, demonstrating highly accurate performance, in some cases even outperforming competitors, and simultaneously being much more resource-friendly.
title Lift What You Can: Green Online Learning with Heterogeneous Ensembles
topic Machine Learning
url https://arxiv.org/abs/2509.18962