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Related papers: SPAR: Support-Preserving Action Rectification

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We consider off-policy evaluation and optimization with continuous action spaces. We focus on observational data where the data collection policy is unknown and needs to be estimated. We take a semi-parametric approach where the value…

Econometrics · Economics 2019-07-23 Mert Demirer , Vasilis Syrgkanis , Greg Lewis , Victor Chernozhukov

Conservatism has led to significant progress in offline reinforcement learning (RL) where an agent learns from pre-collected datasets. However, as many real-world scenarios involve interaction among multiple agents, it is important to…

Machine Learning · Computer Science 2022-04-05 Ling Pan , Longbo Huang , Tengyu Ma , Huazhe Xu

Despite significant progress in alignment, large language models (LLMs) remain vulnerable to adversarial attacks that elicit harmful behaviors. Activation steering techniques offer a promising inference-time intervention approach, but…

Machine Learning · Computer Science 2026-01-28 Quy-Anh Dang , Chris Ngo

Online interactions with the environment to collect data samples for training a Reinforcement Learning (RL) agent is not always feasible due to economic and safety concerns. The goal of Offline Reinforcement Learning is to address this…

Machine Learning · Computer Science 2021-10-05 Chi Zhang , Sanmukh Rao Kuppannagari , Viktor K Prasanna

Traditional language model alignment methods, such as Direct Preference Optimization (DPO), are limited by their dependence on static, pre-collected paired preference data, which hampers their adaptability and practical applicability. To…

Computation and Language · Computer Science 2024-06-03 Yueqin Yin , Zhendong Wang , Yujia Xie , Weizhu Chen , Mingyuan Zhou

We study offline reinforcement learning (RL) which seeks to learn a good policy based on a fixed, pre-collected dataset. A fundamental challenge behind this task is the distributional shift due to the dataset lacking sufficient exploration,…

Machine Learning · Computer Science 2023-10-11 Wenzhuo Zhou

Offline reinforcement learning (RL) offers a promising direction for learning policies from pre-collected datasets without requiring further interactions with the environment. However, existing methods struggle to handle out-of-distribution…

Machine Learning · Computer Science 2024-03-12 Zhepeng Cen , Zuxin Liu , Zitong Wang , Yihang Yao , Henry Lam , Ding Zhao

Off-policy reinforcement learning aims to leverage experience collected from prior policies for sample-efficient learning. However, in practice, commonly used off-policy approximate dynamic programming methods based on Q-learning and…

Machine Learning · Computer Science 2019-11-26 Aviral Kumar , Justin Fu , George Tucker , Sergey Levine

In offline reinforcement learning (RL), we learn policies from fixed datasets without environment interaction. The major challenges are to provide guarantees on the (1) performance and (2) safety of the resulting policy. A technique called…

Machine Learning · Computer Science 2026-05-12 Maris F. L. Galesloot , Thomas Rhemrev , Nils Jansen

In streaming Reinforcement Learning (RL), transitions are observed and discarded immediately after a single update. While this minimizes resource usage for on-device applications, it makes agents notoriously sample-inefficient, since…

Machine Learning · Computer Science 2026-02-11 Nilaksh , Antoine Clavaud , Mathieu Reymond , François Rivest , Sarath Chandar

Sample inefficiency is a long-lasting problem in reinforcement learning (RL). The state-of-the-art estimates the optimal action values while it usually involves an extensive search over the state-action space and unstable optimization.…

Machine Learning · Computer Science 2019-11-27 Kaixiang Lin , Jiayu Zhou

Offline post-training adapts a pretrained robot policy to a target dataset by supervised regression on recorded actions. In practice, robot datasets are heterogeneous: they mix embodiments, camera setups, and demonstrations of varying…

Robotics · Computer Science 2026-03-18 Wanpeng Zhang , Hao Luo , Sipeng Zheng , Yicheng Feng , Haiweng Xu , Ziheng Xi , Chaoyi Xu , Haoqi Yuan , Zongqing Lu

We study the problem of Safe Policy Improvement (SPI) under constraints in the offline Reinforcement Learning (RL) setting. We consider the scenario where: (i) we have a dataset collected under a known baseline policy, (ii) multiple reward…

Machine Learning · Computer Science 2021-11-01 Harsh Satija , Philip S. Thomas , Joelle Pineau , Romain Laroche

Offline policy learning is aimed at learning decision-making policies using existing datasets of trajectories without collecting additional data. The primary motivation for using reinforcement learning (RL) instead of supervised learning…

Class imbalance in real-world data poses a common bottleneck for machine learning tasks, since achieving good generalization on under-represented examples is often challenging. Mitigation strategies, such as under or oversampling the data…

Disordered Systems and Neural Networks · Physics 2025-02-03 Emanuele Loffredo , Mauro Pastore , Simona Cocco , Rémi Monasson

In offline reinforcement learning, weighted regression is a common method to ensure the learned policy stays close to the behavior policy and to prevent selecting out-of-sample actions. In this work, we show that due to the limited…

Machine Learning · Computer Science 2023-03-01 Huayu Chen , Cheng Lu , Chengyang Ying , Hang Su , Jun Zhu

Reinforcement Learning (RL) agents in the real world must satisfy safety constraints in addition to maximizing a reward objective. Model-based RL algorithms hold promise for reducing unsafe real-world actions: they may synthesize policies…

Machine Learning · Computer Science 2021-12-16 Yecheng Jason Ma , Andrew Shen , Osbert Bastani , Dinesh Jayaraman

Offline reinforcement learning methods hold the promise of learning policies from pre-collected datasets without the need to query the environment for new transitions. This setting is particularly well-suited for continuous control robotic…

Machine Learning · Computer Science 2022-03-18 Xi Chen , Ali Ghadirzadeh , Tianhe Yu , Yuan Gao , Jianhao Wang , Wenzhe Li , Bin Liang , Chelsea Finn , Chongjie Zhang

Off-policy deep reinforcement learning (RL) algorithms are incapable of learning solely from batch offline data without online interactions with the environment, due to the phenomenon known as \textit{extrapolation error}. This is often due…

Machine Learning · Computer Science 2019-12-03 Riashat Islam , Komal K. Teru , Deepak Sharma , Joelle Pineau

Off-policy policy optimization is a challenging problem in reinforcement learning (RL). The algorithms designed for this problem often suffer from high variance in their estimators, which results in poor sample efficiency, and have issues…

Machine Learning · Computer Science 2020-09-15 Daoming Lyu , Qi Qi , Mohammad Ghavamzadeh , Hengshuai Yao , Tianbao Yang , Bo Liu