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Related papers: Data Poisoning Attacks in Contextual Bandits

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We propose feature perturbation, a simple yet effective exploration strategy for contextual bandits that injects randomness directly into feature inputs, instead of randomizing unknown parameters or adding noise to rewards. Remarkably, this…

Machine Learning · Computer Science 2025-10-27 Seouh-won Yi , Min-hwan Oh

In this paper, we address the stochastic contextual linear bandit problem, where a decision maker is provided a context (a random set of actions drawn from a distribution). The expected reward of each action is specified by the inner…

Machine Learning · Statistics 2023-05-30 Osama A. Hanna , Lin F. Yang , Christina Fragouli

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 investigate contextual bandits in the presence of side-observations across arms in order to design recommendation algorithms for users connected via social networks. Users in social networks respond to their friends' activity, and hence…

Machine Learning · Computer Science 2020-10-27 Rahul Singh , Fang Liu , Xin Liu , Ness Shroff

We consider the kernelized contextual bandit problem with a large feature space. This problem involves $K$ arms, and the goal of the forecaster is to maximize the cumulative rewards through learning the relationship between the contexts and…

Machine Learning · Statistics 2025-05-21 Shogo Iwazaki , Junpei Komiyama , Masaaki Imaizumi

We present an adaptive learning Intelligent Tutoring System, which uses model-based reinforcement learning in the form of contextual bandits to assign learning activities to students. The model is trained on the trajectories of thousands of…

Computation and Language · Computer Science 2022-07-29 Robert Belfer , Ekaterina Kochmar , Iulian Vlad Serban

Contextual bandit algorithms -- a class of multi-armed bandit algorithms that exploit the contextual information -- have been shown to be effective in solving sequential decision making problems under uncertainty. A common assumption…

Machine Learning · Computer Science 2017-01-25 Linqi Song , Jie Xu

Contextual multi-armed bandit problems arise frequently in important industrial applications. Existing solutions model the context either linearly, which enables uncertainty driven (principled) exploration, or non-linearly, by using…

Machine Learning · Computer Science 2018-07-27 Mark Collier , Hector Urdiales Llorens

A major challenge in contextual bandits is to design general-purpose algorithms that are both practically useful and theoretically well-founded. We present a new technique that has the empirical and computational advantages of…

Machine Learning · Computer Science 2018-03-06 Dylan J. Foster , Alekh Agarwal , Miroslav Dudík , Haipeng Luo , Robert E. Schapire

For infinite action contextual bandits, smoothed regret and reduction to regression results in state-of-the-art online performance with computational cost independent of the action set: unfortunately, the resulting data exhaust does not…

Machine Learning · Computer Science 2023-06-09 Mark Rucker , Yinglun Zhu , Paul Mineiro

Motivated by online recommendation systems, we propose the problem of finding the optimal policy in multitask contextual bandits when a small fraction $\alpha < 1/2$ of tasks (users) are arbitrary and adversarial. The remaining fraction of…

Machine Learning · Computer Science 2022-02-01 Jeongyeol Kwon , Yonathan Efroni , Constantine Caramanis , Shie Mannor

Contextual bandits have become popular as they offer a middle ground between very simple approaches based on multi-armed bandits and very complex approaches using the full power of reinforcement learning. They have demonstrated success in…

Methodology · Statistics 2017-11-13 Kristjan Greenewald , Ambuj Tewari , Predrag Klasnja , Susan Murphy

Recent work shows that when contexts are drawn i.i.d., linear contextual bandits can be reduced to single-context linear bandits. This ``contexts are cheap" perspective is highly advantageous, as it allows for sharper finite-time analyses…

Machine Learning · Computer Science 2026-03-16 Kaan Buyukkalayci , Osama Hanna , Christina Fragouli

We study the $K$-armed contextual dueling bandit problem, a sequential decision making setting in which the learner uses contextual information to make two decisions, but only observes \emph{preference-based feedback} suggesting that one…

Machine Learning · Computer Science 2021-11-25 Aadirupa Saha , Akshay Krishnamurthy

We consider the problem of online boosting for regression tasks, when only limited information is available to the learner. We give an efficient regret minimization method that has two implications: an online boosting algorithm with noisy…

Machine Learning · Computer Science 2020-07-24 Nataly Brukhim , Elad Hazan

Causal knowledge can be used to support decision-making problems. This has been recognized in the causal bandits literature, where a causal (multi-armed) bandit is characterized by a causal graphical model and a target variable. The arms…

Machine Learning · Computer Science 2025-10-14 Francisco N. F. Q. Simoes , Itai Feigenbaum , Mehdi Dastani , Thijs van Ommen

This paper considers the distributed bandit convex optimization problem with time-varying inequality constraints over a network of agents, where the goal is to minimize network regret and cumulative constraint violation. Existing…

Optimization and Control · Mathematics 2024-06-21 Kunpeng Zhang , Xinlei Yi , Guanghui Wen , Ming Cao , Karl H. Johansson , Tianyou Chai , Tao Yang

Data poisoning is an adversarial scenario where an attacker feeds a specially crafted sequence of samples to an online model in order to subvert learning. We introduce Lethean Attack, a novel data poisoning technique that induces…

Cryptography and Security · Computer Science 2020-11-26 Eyal Perry

This paper introduces a new principled approach for off-policy learning in contextual bandits. Unlike previous work, our approach does not derive learning principles from intractable or loose bounds. We analyse the problem through the…

Machine Learning · Statistics 2023-05-30 Otmane Sakhi , Pierre Alquier , Nicolas Chopin

Solutions to address the periodic review inventory control problem with nonstationary random demand, lost sales, and stochastic vendor lead times typically involve making strong assumptions on the dynamics for either approximation or…

Machine Learning · Statistics 2023-10-26 Dean Foster , Randy Jia , Dhruv Madeka