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Related papers: Safe Exploration for Optimizing Contextual Bandits

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We consider the problem of contextual bandits and imitation learning, where the learner lacks direct knowledge of the executed action's reward. Instead, the learner can actively query an expert at each round to compare two actions and…

Machine Learning · Computer Science 2023-07-25 Ayush Sekhari , Karthik Sridharan , Wen Sun , Runzhe Wu

We propose a new sequential decision-making setting, combining key aspects of two established online learning problems with bandit feedback. The optimal action to play at any given moment is contingent on an underlying changing state which…

Machine Learning · Computer Science 2023-11-07 Alexander Galozy , Slawomir Nowaczyk , Mattias Ohlsson

Contextual bandit algorithms are sensitive to the estimation method of the outcome model as well as the exploration method used, particularly in the presence of rich heterogeneity or complex outcome models, which can lead to difficult…

Machine Learning · Computer Science 2018-12-18 Maria Dimakopoulou , Zhengyuan Zhou , Susan Athey , Guido Imbens

Contextual bandits are a common problem faced by machine learning practitioners in domains as diverse as hypothesis testing to product recommendations. There have been a lot of approaches in exploiting rich data representations for…

Computer Vision and Pattern Recognition · Computer Science 2020-03-20 Aniket Anand Deshmukh , Abhimanu Kumar , Levi Boyles , Denis Charles , Eren Manavoglu , Urun Dogan

Most contextual bandit algorithms minimize regret against the best fixed policy, a questionable benchmark for non-stationary environments that are ubiquitous in applications. In this work, we develop several efficient contextual bandit…

Machine Learning · Computer Science 2019-04-05 Haipeng Luo , Chen-Yu Wei , Alekh Agarwal , John Langford

Designing efficient exploration is central to Reinforcement Learning due to the fundamental problem posed by the exploration-exploitation dilemma. Bayesian exploration strategies like Thompson Sampling resolve this trade-off in a principled…

Machine Learning · Computer Science 2021-10-27 Rong Zhu , Mattia Rigotti

Contextual bandit algorithms have become popular for online recommendation systems such as Digg, Yahoo! Buzz, and news recommendation in general. \emph{Offline} evaluation of the effectiveness of new algorithms in these applications is…

Machine Learning · Computer Science 2015-03-13 Lihong Li , Wei Chu , John Langford , Xuanhui Wang

Many efficient algorithms with strong theoretical guarantees have been proposed for the contextual multi-armed bandit problem. However, applying these algorithms in practice can be difficult because they require domain expertise to build…

Machine Learning · Computer Science 2018-10-23 Adam N. Elmachtoub , Ryan McNellis , Sechan Oh , Marek Petrik

We introduce the problem of model selection for contextual bandits, where a learner must adapt to the complexity of the optimal policy while balancing exploration and exploitation. Our main result is a new model selection guarantee for…

Machine Learning · Computer Science 2019-11-15 Dylan J. Foster , Akshay Krishnamurthy , Haipeng Luo

Most bandit policies are designed to either minimize regret in any problem instance, making very few assumptions about the underlying environment, or in a Bayesian sense, assuming a prior distribution over environment parameters. The former…

Machine Learning · Computer Science 2021-01-07 Branislav Kveton , Martin Mladenov , Chih-Wei Hsu , Manzil Zaheer , Csaba Szepesvari , Craig Boutilier

The stochastic contextual bandit problem, which models the trade-off between exploration and exploitation, has many real applications, including recommender systems, online advertising and clinical trials. As many other machine learning…

Machine Learning · Statistics 2022-06-14 Qin Ding , Yue Kang , Yi-Wei Liu , Thomas C. M. Lee , Cho-Jui Hsieh , James Sharpnack

Contextual bandit algorithms are at the core of many applications, including recommender systems, clinical trials, and optimal portfolio selection. One of the most popular problems studied in the contextual bandit literature is to maximize…

Machine Learning · Computer Science 2023-10-24 Siddhant Chaudhary , Abhishek Sinha

We address policy learning with logged data in contextual bandits. Current offline-policy learning algorithms are mostly based on inverse propensity score (IPS) weighting requiring the logging policy to have \emph{full support} i.e. a…

Machine Learning · Statistics 2021-07-27 Hung Tran-The , Sunil Gupta , Thanh Nguyen-Tang , Santu Rana , Svetha Venkatesh

Contextual bandits can solve a huge range of real-world problems. However, current popular algorithms to solve them either rely on linear models, or unreliable uncertainty estimation in non-linear models, which are required to deal with the…

Machine Learning · Computer Science 2023-02-01 Adam Elwood , Marco Leonardi , Ashraf Mohamed , Alessandro Rozza

A key goal in stochastic contextual linear bandits is to efficiently learn a near-optimal policy. Prior algorithms for this problem learn a policy by strategically sampling actions but naively (passively) sampling contexts from the…

Machine Learning · Computer Science 2026-05-26 Emma Brunskill , Ishani Karmarkar , Zhaoqi Li

We study the sequential batch learning problem in linear contextual bandits with finite action sets, where the decision maker is constrained to split incoming individuals into (at most) a fixed number of batches and can only observe…

Machine Learning · Computer Science 2020-04-15 Yanjun Han , Zhengqing Zhou , Zhengyuan Zhou , Jose Blanchet , Peter W. Glynn , Yinyu Ye

We consider an online decision making setting known as contextual bandit problem, and propose an approach for improving contextual bandit performance by using an adaptive feature extraction (representation learning) based on online…

Artificial Intelligence · Computer Science 2020-09-15 Baihan Lin , Djallel Bouneffouf , Guillermo Cecchi , Irina Rish

We introduce the cram method as a general statistical framework for evaluating the final learned policy from a multi-armed contextual bandit algorithm, using the dataset generated by the same bandit algorithm. The proposed on-policy…

Machine Learning · Computer Science 2025-04-16 Zeyang Jia , Kosuke Imai , Michael Lingzhi Li

We consider a novel variant of the contextual bandit problem (i.e., the multi-armed bandit with side-information, or context, available to a decision-maker) where the context used at each decision may be corrupted ("useless context"). This…

Machine Learning · Computer Science 2020-06-30 Djallel Bouneffouf

Contextual bandit algorithms provide principled online learning solutions to balance the exploitation-exploration trade-off in various applications such as recommender systems. However, the learning speed of the traditional contextual…

Machine Learning · Computer Science 2020-01-28 Xiaoying Zhang , Hong Xie , Hang Li , John C. S. Lui