Exploration-Driven Policy Optimization in RLHF: Theoretical Insights on Efficient Data Utilization

Fuente: arXiv
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Autori principali: Du, Yihan, Winnicki, Anna, Dalal, Gal, Mannor, Shie, Srikant, R.
Natura: Preprint
Pubblicazione: 2024
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author Du, Yihan
Winnicki, Anna
Dalal, Gal
Mannor, Shie
Srikant, R.
author_facet Du, Yihan
Winnicki, Anna
Dalal, Gal
Mannor, Shie
Srikant, R.
contents Reinforcement Learning from Human Feedback (RLHF) has achieved impressive empirical successes while relying on a small amount of human feedback. However, there is limited theoretical justification for this phenomenon. Additionally, most recent studies focus on value-based algorithms despite the recent empirical successes of policy-based algorithms. In this work, we consider an RLHF algorithm based on policy optimization (PO-RLHF). The algorithm is based on the popular Policy Cover-Policy Gradient (PC-PG) algorithm, which assumes knowledge of the reward function. In PO-RLHF, knowledge of the reward function is not assumed, and the algorithm uses trajectory-based comparison feedback to infer the reward function. We provide performance bounds for PO-RLHF with low query complexity, which provides insight into why a small amount of human feedback may be sufficient to achieve good performance with RLHF. A key novelty is a trajectory-level elliptical potential analysis, which bounds the reward estimation error when comparison feedback (rather than numerical reward observation) is given. We provide and analyze algorithms PG-RLHF and NN-PG-RLHF for two settings: linear and neural function approximation, respectively.
format Preprint
id arxiv_https___arxiv_org_abs_2402_10342
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Exploration-Driven Policy Optimization in RLHF: Theoretical Insights on Efficient Data Utilization
Du, Yihan
Winnicki, Anna
Dalal, Gal
Mannor, Shie
Srikant, R.
Machine Learning
Artificial Intelligence
Computation and Language
Reinforcement Learning from Human Feedback (RLHF) has achieved impressive empirical successes while relying on a small amount of human feedback. However, there is limited theoretical justification for this phenomenon. Additionally, most recent studies focus on value-based algorithms despite the recent empirical successes of policy-based algorithms. In this work, we consider an RLHF algorithm based on policy optimization (PO-RLHF). The algorithm is based on the popular Policy Cover-Policy Gradient (PC-PG) algorithm, which assumes knowledge of the reward function. In PO-RLHF, knowledge of the reward function is not assumed, and the algorithm uses trajectory-based comparison feedback to infer the reward function. We provide performance bounds for PO-RLHF with low query complexity, which provides insight into why a small amount of human feedback may be sufficient to achieve good performance with RLHF. A key novelty is a trajectory-level elliptical potential analysis, which bounds the reward estimation error when comparison feedback (rather than numerical reward observation) is given. We provide and analyze algorithms PG-RLHF and NN-PG-RLHF for two settings: linear and neural function approximation, respectively.
title Exploration-Driven Policy Optimization in RLHF: Theoretical Insights on Efficient Data Utilization
topic Machine Learning
Artificial Intelligence
Computation and Language
url https://arxiv.org/abs/2402.10342