Decision Making in Hybrid Environments: A Model Aggregation Approach

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Liu, Haolin, Wei, Chen-Yu, Zimmert, Julian
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866912355700441088
author Liu, Haolin
Wei, Chen-Yu
Zimmert, Julian
author_facet Liu, Haolin
Wei, Chen-Yu
Zimmert, Julian
contents Recent work by Foster et al. (2021, 2022, 2023b) and Xu and Zeevi (2023) developed the framework of decision estimation coefficient (DEC) that characterizes the complexity of general online decision making problems and provides a general algorithm design principle. These works, however, either focus on the pure stochastic regime where the world remains fixed over time, or the pure adversarial regime where the world arbitrarily changes over time. For the hybrid regime where the dynamics of the world is fixed while the reward arbitrarily changes, they only give pessimistic bounds on the decision complexity. In this work, we propose a general extension of DEC that more precisely characterizes this case. Besides applications in special cases, our framework leads to a flexible algorithm design where the learner learns over subsets of the hypothesis set, trading estimation complexity with decision complexity, which could be of independent interest. Our work covers model-based learning and model-free learning in the hybrid regime, with a newly proposed extension of the bilinear classes (Du et al., 2021) to the adversarial-reward case. In addition, our method improves the best-known regret bounds for linear Q*/V* MDPs in the pure stochastic regime.
format Preprint
id arxiv_https___arxiv_org_abs_2502_05974
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Decision Making in Hybrid Environments: A Model Aggregation Approach
Liu, Haolin
Wei, Chen-Yu
Zimmert, Julian
Machine Learning
Recent work by Foster et al. (2021, 2022, 2023b) and Xu and Zeevi (2023) developed the framework of decision estimation coefficient (DEC) that characterizes the complexity of general online decision making problems and provides a general algorithm design principle. These works, however, either focus on the pure stochastic regime where the world remains fixed over time, or the pure adversarial regime where the world arbitrarily changes over time. For the hybrid regime where the dynamics of the world is fixed while the reward arbitrarily changes, they only give pessimistic bounds on the decision complexity. In this work, we propose a general extension of DEC that more precisely characterizes this case. Besides applications in special cases, our framework leads to a flexible algorithm design where the learner learns over subsets of the hypothesis set, trading estimation complexity with decision complexity, which could be of independent interest. Our work covers model-based learning and model-free learning in the hybrid regime, with a newly proposed extension of the bilinear classes (Du et al., 2021) to the adversarial-reward case. In addition, our method improves the best-known regret bounds for linear Q*/V* MDPs in the pure stochastic regime.
title Decision Making in Hybrid Environments: A Model Aggregation Approach
topic Machine Learning
url https://arxiv.org/abs/2502.05974