Exploiting Causal Graph Priors with Posterior Sampling for Reinforcement Learning

Fuente: arXiv
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Main Authors: Mutti, Mirco, De Santi, Riccardo, Restelli, Marcello, Marx, Alexander, Ramponi, Giorgia
Format: Preprint
Published: 2023
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author Mutti, Mirco
De Santi, Riccardo
Restelli, Marcello
Marx, Alexander
Ramponi, Giorgia
author_facet Mutti, Mirco
De Santi, Riccardo
Restelli, Marcello
Marx, Alexander
Ramponi, Giorgia
contents Posterior sampling allows exploitation of prior knowledge on the environment's transition dynamics to improve the sample efficiency of reinforcement learning. The prior is typically specified as a class of parametric distributions, the design of which can be cumbersome in practice, often resulting in the choice of uninformative priors. In this work, we propose a novel posterior sampling approach in which the prior is given as a (partial) causal graph over the environment's variables. The latter is often more natural to design, such as listing known causal dependencies between biometric features in a medical treatment study. Specifically, we propose a hierarchical Bayesian procedure, called C-PSRL, simultaneously learning the full causal graph at the higher level and the parameters of the resulting factored dynamics at the lower level. We provide an analysis of the Bayesian regret of C-PSRL that explicitly connects the regret rate with the degree of prior knowledge. Our numerical evaluation conducted in illustrative domains confirms that C-PSRL strongly improves the efficiency of posterior sampling with an uninformative prior while performing close to posterior sampling with the full causal graph.
format Preprint
id arxiv_https___arxiv_org_abs_2310_07518
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Exploiting Causal Graph Priors with Posterior Sampling for Reinforcement Learning
Mutti, Mirco
De Santi, Riccardo
Restelli, Marcello
Marx, Alexander
Ramponi, Giorgia
Machine Learning
Posterior sampling allows exploitation of prior knowledge on the environment's transition dynamics to improve the sample efficiency of reinforcement learning. The prior is typically specified as a class of parametric distributions, the design of which can be cumbersome in practice, often resulting in the choice of uninformative priors. In this work, we propose a novel posterior sampling approach in which the prior is given as a (partial) causal graph over the environment's variables. The latter is often more natural to design, such as listing known causal dependencies between biometric features in a medical treatment study. Specifically, we propose a hierarchical Bayesian procedure, called C-PSRL, simultaneously learning the full causal graph at the higher level and the parameters of the resulting factored dynamics at the lower level. We provide an analysis of the Bayesian regret of C-PSRL that explicitly connects the regret rate with the degree of prior knowledge. Our numerical evaluation conducted in illustrative domains confirms that C-PSRL strongly improves the efficiency of posterior sampling with an uninformative prior while performing close to posterior sampling with the full causal graph.
title Exploiting Causal Graph Priors with Posterior Sampling for Reinforcement Learning
topic Machine Learning
url https://arxiv.org/abs/2310.07518