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Related papers: Policy Gradient with Active Importance Sampling

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Policy gradient methods are powerful reinforcement learning algorithms and have been demonstrated to solve many complex tasks. However, these methods are also data-inefficient, afflicted with high variance gradient estimates, and frequently…

Machine Learning · Computer Science 2019-05-15 Andreas Doerr , Michael Volpp , Marc Toussaint , Sebastian Trimpe , Christian Daniel

Stateful policies play an important role in reinforcement learning, such as handling partially observable environments, enhancing robustness, or imposing an inductive bias directly into the policy structure. The conventional method for…

Machine Learning · Computer Science 2023-11-08 Firas Al-Hafez , Guoping Zhao , Jan Peters , Davide Tateo

This paper introduces two novel modifications to the Dynamic sAmpling Policy Optimization (DAPO) algorithm [1], approached from a mixed-policy perspective. Standard policy gradient methods can suffer from instability and sample…

Machine Learning · Computer Science 2025-08-20 Hongze Tan , Yuchen Li

Recently, the impressive empirical success of policy gradient (PG) methods has catalyzed the development of their theoretical foundations. Despite the huge efforts directed at the design of efficient stochastic PG-type algorithms, the…

Machine Learning · Computer Science 2023-11-09 Ilyas Fatkhullin , Anas Barakat , Anastasia Kireeva , Niao He

We introduce a novel policy learning method that integrates analytical gradients from differentiable environments with the Proximal Policy Optimization (PPO) algorithm. To incorporate analytical gradients into the PPO framework, we…

Machine Learning · Computer Science 2023-12-15 Sanghyun Son , Laura Yu Zheng , Ryan Sullivan , Yi-Ling Qiao , Ming C. Lin

This paper introduces the Active-Importance-Sampling Actor-Critic (AISAC) algorithm, an extension of the Actor-Critic framework for reducing variance in policy gradient estimation. AISAC optimizes the behavior policy to minimize gradient…

Machine Learning · Computer Science 2026-05-11 Majid Molaei , Gabor Paczolay , Matteo Papini , Alberto Maria Metelli , Marcello Restelli

The policy gradient method enjoys the simplicity of the objective where the agent optimizes the cumulative reward directly. Moreover, in the continuous action domain, parameterized distribution of action distribution allows easy control of…

Machine Learning · Computer Science 2022-12-16 Md Masudur Rahman , Yexiang Xue

Policy gradient (PG) gives rise to a rich class of reinforcement learning (RL) methods. Recently, there has been an emerging trend to accelerate the existing PG methods such as REINFORCE by the \emph{variance reduction} techniques. However,…

Machine Learning · Computer Science 2021-05-31 Junyu Zhang , Chengzhuo Ni , Zheng Yu , Csaba Szepesvari , Mengdi Wang

Importance Sampling (IS) is a method for approximating expectations under a target distribution using independent samples from a proposal distribution and the associated importance weights. In many applications, the target distribution is…

Machine Learning · Statistics 2022-09-14 Gabriel Cardoso , Sergey Samsonov , Achille Thin , Eric Moulines , Jimmy Olsson

While reinforcement learning (RL) has shown promising performance, its sample complexity continues to be a substantial hurdle, restricting its broader application across a variety of domains. Imitation learning (IL) utilizes oracles to…

Machine Learning · Computer Science 2025-08-12 Xuefeng Liu , Takuma Yoneda , Rick L. Stevens , Matthew R. Walter , Yuxin Chen

Policy gradient (PG) is widely used in reinforcement learning due to its scalability and good performance. In recent years, several variance-reduced PG methods have been proposed with a theoretical guarantee of converging to an approximate…

Machine Learning · Computer Science 2025-10-01 Sadegh Khorasani , Saber Salehkaleybar , Negar Kiyavash , Niao He , Matthias Grossglauser

Deep reinforcement learning has been able to solve various tasks successfully, however, due to the construction of policy gradient and training dynamics, tuning deep reinforcement learning models remains challenging. As one of the most…

Machine Learning · Computer Science 2026-02-11 Hanyong Wang , Menglong Yang

We introduce Phasic Policy Gradient (PPG), a reinforcement learning framework which modifies traditional on-policy actor-critic methods by separating policy and value function training into distinct phases. In prior methods, one must choose…

Machine Learning · Computer Science 2020-09-10 Karl Cobbe , Jacob Hilton , Oleg Klimov , John Schulman

This paper investigates the use of retrospective approximation solution paradigm in solving risk-averse optimization problems effectively via importance sampling (IS). While IS serves as a prominent means for tackling the large sample…

Risk Management · Quantitative Finance 2022-06-28 Anand Deo , Karthyek Murthy , Tirtho Sarker

Direct optimization is an appealing framework that replaces integration with optimization of a random objective for approximating gradients in models with discrete random variables. A$^\star$ sampling is a framework for optimizing such…

Machine Learning · Computer Science 2020-10-26 Guy Lorberbom , Chris J. Maddison , Nicolas Heess , Tamir Hazan , Daniel Tarlow

This note introduces Isometric Policy Optimization (ISOPO), an efficient method to approximate the natural policy gradient in a single gradient step. In comparison, existing proximal policy methods such as GRPO or CISPO use multiple…

Machine Learning · Computer Science 2026-01-01 Nilin Abrahamsen

Importance sampling (IS) is a technique that enables statistical estimation of output performance at multiple input distributions from a single nominal input distribution. IS is commonly used in Monte Carlo simulation for variance reduction…

Methodology · Statistics 2025-05-07 Yijuan Liang , Guangxin Jiang , Michael C. Fu

Importance sampling (IS) is a Monte Carlo methodology that allows for approximation of a target distribution using weighted samples generated from another proposal distribution. Adaptive importance sampling (AIS) implements an iterative…

Computation · Statistics 2018-06-04 Yousef El-Laham , Victor Elvira , Monica F. Bugallo

Policy gradient methods ignore the potential value of adjusting environment variables: unobservable state features that are randomly determined by the environment in a physical setting, but are controllable in a simulator. This can lead to…

Machine Learning · Computer Science 2019-05-28 Supratik Paul , Michael A. Osborne , Shimon Whiteson

Off-policy model-free deep reinforcement learning methods using previously collected data can improve sample efficiency over on-policy policy gradient techniques. On the other hand, on-policy algorithms are often more stable and easier to…

Machine Learning · Computer Science 2017-06-02 Shixiang Gu , Timothy Lillicrap , Zoubin Ghahramani , Richard E. Turner , Bernhard Schölkopf , Sergey Levine