Investigating the Interplay of Prioritized Replay and Generalization

Fuente: arXiv
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Main Authors: Panahi, Parham Mohammad, Patterson, Andrew, White, Martha, White, Adam
Format: Preprint
Published: 2024
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author Panahi, Parham Mohammad
Patterson, Andrew
White, Martha
White, Adam
author_facet Panahi, Parham Mohammad
Patterson, Andrew
White, Martha
White, Adam
contents Experience replay, the reuse of past data to improve sample efficiency, is ubiquitous in reinforcement learning. Though a variety of smart sampling schemes have been introduced to improve performance, uniform sampling by far remains the most common approach. One exception is Prioritized Experience Replay (PER), where sampling is done proportionally to TD errors, inspired by the success of prioritized sweeping in dynamic programming. The original work on PER showed improvements in Atari, but follow-up results were mixed. In this paper, we investigate several variations on PER, to attempt to understand where and when PER may be useful. Our findings in prediction tasks reveal that while PER can improve value propagation in tabular settings, behavior is significantly different when combined with neural networks. Certain mitigations $-$ like delaying target network updates to control generalization and using estimates of expected TD errors in PER to avoid chasing stochasticity $-$ can avoid large spikes in error with PER and neural networks but generally do not outperform uniform replay. In control tasks, none of the prioritized variants consistently outperform uniform replay. We present new insight into the interaction between prioritization, bootstrapping, and neural networks and propose several improvements for PER in tabular settings and noisy domains.
format Preprint
id arxiv_https___arxiv_org_abs_2407_09702
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Investigating the Interplay of Prioritized Replay and Generalization
Panahi, Parham Mohammad
Patterson, Andrew
White, Martha
White, Adam
Machine Learning
Artificial Intelligence
Experience replay, the reuse of past data to improve sample efficiency, is ubiquitous in reinforcement learning. Though a variety of smart sampling schemes have been introduced to improve performance, uniform sampling by far remains the most common approach. One exception is Prioritized Experience Replay (PER), where sampling is done proportionally to TD errors, inspired by the success of prioritized sweeping in dynamic programming. The original work on PER showed improvements in Atari, but follow-up results were mixed. In this paper, we investigate several variations on PER, to attempt to understand where and when PER may be useful. Our findings in prediction tasks reveal that while PER can improve value propagation in tabular settings, behavior is significantly different when combined with neural networks. Certain mitigations $-$ like delaying target network updates to control generalization and using estimates of expected TD errors in PER to avoid chasing stochasticity $-$ can avoid large spikes in error with PER and neural networks but generally do not outperform uniform replay. In control tasks, none of the prioritized variants consistently outperform uniform replay. We present new insight into the interaction between prioritization, bootstrapping, and neural networks and propose several improvements for PER in tabular settings and noisy domains.
title Investigating the Interplay of Prioritized Replay and Generalization
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2407.09702