Beyond expected return: accounting for policy reproducibility when evaluating reinforcement learning algorithms
File(s)2312.07178v2.pdf (983.05 KB)
Accepted version
Author(s)
Flageat, Manon
Lim, Bryan
Cully, Antoine
Type
Conference Paper
Abstract
Many applications in Reinforcement Learning (RL) usually have noise or stochasticity present in the environment. Beyond their impact on learning, these uncertainties lead the exact same policy to perform differently, i.e. yield different return, from one roll-out to another. Common evaluation procedures in RL summarise the consequent return distributions using solely the expected return, which does not account for the spread of the distribution. Our work defines this spread as the policy reproducibility: the ability of a policy to obtain similar performance when rolled out many times, a crucial property in some real-world applications. We highlight that existing procedures that only use the expected return are limited on two fronts: first an infinite number of return distributions with a wide range of performance-reproducibility trade-offs can have the same expected return, limiting its effectiveness when used for comparing policies; second, the expected return metric does not leave any room for practitioners to choose the best trade-off value for considered applications. In this work, we address these limitations by recommending the use of Lower Confidence Bound, a metric taken from Bayesian optimisation that provides the user with a preference parameter to choose a desired performance-reproducibility trade-off. We also formalise and quantify policy reproducibility, and demonstrate the benefit of our metrics using extensive experiments of popular RL algorithms on common uncertain RL tasks.
Date Issued
2024-03-24
Date Acceptance
2023-12-19
Citation
Proceedings of the ... AAAI Conference on Artificial Intelligence. AAAI Conference on Artificial Intelligence, 2024, 38 (11)
ISSN
2159-5399
Publisher
AAAI
Journal / Book Title
Proceedings of the ... AAAI Conference on Artificial Intelligence. AAAI Conference on Artificial Intelligence
Volume
38
Issue
11
Copyright Statement
© 2024, Association for the Advancement of Artificial Intelligence.
Source
AAAI Conference on Artificial Intelligence
Publication Status
Published
Start Date
2024-02-20
Finish Date
2024-02-27
Coverage Spatial
Vancouver, Canada