SafetyTrustworthinessAccountabilitycs.LG
RA-PbRL: Provably Efficient Risk-Aware Preference-Based Reinforcement Learning
Yujie Zhao, Jose Efraim Aguilar Escamill, Weyl Lu, Huazheng Wang
October 31, 2024
Neural Information Processing Systems
11 citations
2 influential
Key Takeaways
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Risk-aware objectives matter for high-stakes AI applications: The paper identifies that current approaches to learning from human feedback focus only on average performance, which is inadequate for safety-critical domains like healthcare, autonomous driving, and AI safety where worst-case scenarios must be considered.
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Two practical risk-aware approaches are now theoretically validated: The research proves that "nested" and "static quantile" risk objectives can be effectively applied to preference-based learning, providing mathematical guarantees that these methods improve performance over episodes in a measurable way (sublinear regret bounds).
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The RA-PbRL algorithm provides a concrete solution: The paper introduces a specific algorithm that can optimize for risk-aware objectives when learning from human preferences, addressing a gap where previous methods couldn't handle scenarios where only a single episode's reward matters (common in real-world deployments).
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This bridges RLHF and safety considerations: By connecting Reinforcement Learning from Human Feedback—the technique behind systems like ChatGPT—to risk-aware decision-making, the work suggests that aligning AI systems with human values should explicitly account for avoiding rare but catastrophic failures, not just maximizing average outcomes.
Abstract
Reinforcement Learning from Human Feedback (RLHF) has recently surged in popularity, particularly for aligning large language models and other AI systems with human intentions. At its core, RLHF can be viewed as a specialized instance of Preference-based Reinforcement Learning (PbRL), where the preferences specifically originate from human judgments rather than arbitrary evaluators. Despite this connection, most existing approaches in both RLHF and PbRL primarily focus on optimizing a mean reward objective, neglecting scenarios that necessitate risk-awareness, such as AI safety, healthcare, and autonomous driving. These scenarios often operate under a one-episode-reward setting, which makes conventional risk-sensitive objectives inapplicable. To address this, we explore and prove the applicability of two risk-aware objectives to PbRL : nested and static quantile risk objectives. We also introduce Risk-AwarePbRL (RA-PbRL), an algorithm designed to optimize both nested and static objectives. Additionally, we provide a theoretical analysis of the regret upper bounds, demonstrating that they are sublinear with respect to the number of episodes, and present empirical results to support our findings. Our code is available in https://github.com/aguilarjose11/PbRLNeurips.
Paper Info
arXiv ID2410.23569
PublishedOctober 31, 2024
RevisedJanuary 9, 2025
Citations
11
Influential
2
Relevance78%
VenueNeural Information Processing Systems
TypeJournalArticle
Categorycs.LG
Responsible AI Topics
SafetyTrustworthinessAccountability
Links
Citation data from Semantic Scholar