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Related papers: A Survey on Contextual Multi-armed Bandits

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In many applications, e.g. in healthcare and e-commerce, the goal of a contextual bandit may be to learn an optimal treatment assignment policy at the end of the experiment. That is, to minimize simple regret. However, this objective…

Machine Learning · Computer Science 2023-11-06 Sanath Kumar Krishnamurthy , Ruohan Zhan , Susan Athey , Emma Brunskill

In this paper, we investigate the impact of context diversity on stochastic linear contextual bandits. As opposed to the previous view that contexts lead to more difficult bandit learning, we show that when the contexts are sufficiently…

Machine Learning · Computer Science 2020-03-06 Weiqiang Wu , Jing Yang , Cong Shen

Contextual bandits have the same exploration-exploitation trade-off as standard multi-armed bandits. On adding positive externalities that decay with time, this problem becomes much more difficult as wrong decisions at the start are hard to…

Machine Learning · Computer Science 2019-11-15 Harsh Deshpande , Vishal Jain , Sharayu Moharir

Contextual bandits are widely used in industrial personalization systems. These online learning frameworks learn a treatment assignment policy in the presence of treatment effects that vary with the observed contextual features of the…

Machine Learning · Computer Science 2022-05-11 Claudia Roberts , Maria Dimakopoulou , Qifeng Qiao , Ashok Chandrashekhar , Tony Jebara

We study budget-constrained contextual bandits with adversarial contexts, where each action yields a random reward and incurs a random cost. We adopt the standard realizability assumption: conditioned on the observed context, rewards and…

Machine Learning · Computer Science 2026-05-08 Dhruv Sarkar , Abhishek Sinha

Stochastic linear contextual bandit algorithms have substantial applications in practice, such as recommender systems, online advertising, clinical trials, etc. Recent works show that optimal bandit algorithms are vulnerable to adversarial…

Machine Learning · Statistics 2023-01-31 Qin Ding , Cho-Jui Hsieh , James Sharpnack

The problem of multi-armed bandits (MAB) asks to make sequential decisions while balancing between exploitation and exploration, and have been successfully applied to a wide range of practical scenarios. Various algorithms have been…

Machine Learning · Computer Science 2022-02-24 Xiaojin Zhang , Shuai Li , Weiwen Liu , Shengyu Zhang

We examine a multi-armed bandit problem with contextual information, where the objective is to ensure that each arm receives a minimum aggregated reward across contexts while simultaneously maximizing the total cumulative reward. This…

Machine Learning · Computer Science 2025-10-15 Ahmed Ben Yahmed , Hafedh El Ferchichi , Marc Abeille , Vianney Perchet

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

Designing efficient general-purpose contextual bandit algorithms that work with large -- or even continuous -- action spaces would facilitate application to important scenarios such as information retrieval, recommendation systems, and…

Machine Learning · Computer Science 2022-07-14 Yinglun Zhu , Paul Mineiro

We create a computationally tractable algorithm for contextual bandits with continuous actions having unknown structure. Our reduction-style algorithm composes with most supervised learning representations. We prove that it works in a…

Machine Learning · Computer Science 2020-12-07 Maryam Majzoubi , Chicheng Zhang , Rajan Chari , Akshay Krishnamurthy , John Langford , Aleksandrs Slivkins

We study a novel multi-armed bandit problem that models the challenge faced by a company wishing to explore new strategies to maximize revenue whilst simultaneously maintaining their revenue above a fixed baseline, uniformly over time.…

Machine Learning · Statistics 2016-02-16 Yifan Wu , Roshan Shariff , Tor Lattimore , Csaba Szepesvári

This paper studies the adversarial graphical contextual bandits, a variant of adversarial multi-armed bandits that leverage two categories of the most common side information: \emph{contexts} and \emph{side observations}. In this setting, a…

Machine Learning · Computer Science 2021-02-18 Lingda Wang , Bingcong Li , Huozhi Zhou , Georgios B. Giannakis , Lav R. Varshney , Zhizhen Zhao

We develop a novel and generic algorithm for the adversarial multi-armed bandit problem (or more generally the combinatorial semi-bandit problem). When instantiated differently, our algorithm achieves various new data-dependent regret…

Machine Learning · Computer Science 2018-06-08 Chen-Yu Wei , Haipeng Luo

We study Pareto optimality in multi-objective multi-armed bandit by providing a formulation of adversarial multi-objective multi-armed bandit and defining its Pareto regrets that can be applied to both stochastic and adversarial settings.…

Machine Learning · Computer Science 2023-06-01 Mengfan Xu , Diego Klabjan

Contextual multi-armed bandits are classical models in reinforcement learning for sequential decision-making associated with individual information. A widely-used policy for bandits is Thompson Sampling, where samples from a data-driven…

Machine Learning · Statistics 2021-11-30 Hongju Park , Mohamad Kazem Shirani Faradonbeh

In a multi-armed bandit (MAB) problem, an online algorithm makes a sequence of choices. In each round it chooses from a time-invariant set of alternatives and receives the payoff associated with this alternative. While the case of small…

Data Structures and Algorithms · Computer Science 2014-05-21 Aleksandrs Slivkins

Multi-armed bandits a simple but very powerful framework for algorithms that make decisions over time under uncertainty. An enormous body of work has accumulated over the years, covered in several books and surveys. This book provides a…

Machine Learning · Computer Science 2024-04-05 Aleksandrs Slivkins

Stochastic multi-armed bandits form a class of online learning problems that have important applications in online recommendation systems, adaptive medical treatment, and many others. Even though potential attacks against these learning…

Machine Learning · Computer Science 2019-05-17 Fang Liu , Ness Shroff

Contextual bandits with average-case statistical guarantees are inadequate in risk-averse situations because they might trade off degraded worst-case behaviour for better average performance. Designing a risk-averse contextual bandit is…

Machine Learning · Statistics 2023-07-11 Mónika Farsang , Paul Mineiro , Wangda Zhang