Fully Offline Reinforcement Learning
arXiv:2505.22442
The paper proposes fully offline reinforcement learning methods that use Bayesian model-based techniques to learn dynamics and evaluate policies without any online interaction, enabling offline hyperparameter tuning and providing theoretical guarantees.
Abstract
Offline RL (ORL) promises safe and sample-efficient deployment but existing methods rely on undocumented online interactions for hyperparameter tuning and lack reliable fully offline estimates of initial online performance. We introduce SOReL, a fully offline Bayesian model-based RL method that learns a posterior over dynamics, estimates policy value via predictive uncertainty, and enables complete offline hyperparameter selection. We further propose TOReL, which extends this tuning framework to arbitrary model-free and model-based ORL algorithms. We provide a regret analysis showing that Bayesian offline RL achieves the minimax-optimal parametric rate under standard regularity conditions. Together, our methods establish a practical and theoretically grounded framework for fully offline RL.