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Related papers: EVaR-Optimal Arm Identification in Bandits

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Fixed-budget best-arm identification (BAI) is a bandit problem where the agent maximizes the probability of identifying the optimal arm within a fixed budget of observations. In this work, we study this problem in the Bayesian setting. We…

Machine Learning · Computer Science 2023-06-16 Alexia Atsidakou , Sumeet Katariya , Sujay Sanghavi , Branislav Kveton

In fixed-confidence best arm identification (BAI), the objective is to quickly identify the optimal option while controlling the probability of error below a desired threshold. Despite the plethora of BAI algorithms, existing methods…

Machine Learning · Computer Science 2026-01-05 Brian M. Cho , Nathan Kallus

The classical multi-armed bandit (MAB) problem involves a learner and a collection of K independent arms, each with its own ex ante unknown independent reward distribution. At each one of a finite number of rounds, the learner selects one…

Optimization and Control · Mathematics 2024-05-07 Hongda Hu , Arthur Charpentier , Mario Ghossoub , Alexander Schied

We consider the best arm identification problem in the stochastic multi-armed bandit framework where each arm has a tiny probability of realizing large rewards while with overwhelming probability the reward is zero. A key application of…

Machine Learning · Computer Science 2023-03-15 Anirban Bhattacharjee , Sushant Vijayan , Sandeep K Juneja

We consider the question introduced by \cite{Mason2020} of identifying all the $\varepsilon$-optimal arms in a finite stochastic multi-armed bandit with Gaussian rewards. We give two lower bounds on the sample complexity of any algorithm…

Machine Learning · Statistics 2022-04-07 Aymen Al Marjani , Tomáš Kocák , Aurélien Garivier

The best arm identification problem in the multi-armed bandit setting is an excellent model of many real-world decision-making problems, yet it fails to capture the fact that in the real-world, safety constraints often must be met while…

Machine Learning · Computer Science 2021-11-25 Zhenlin Wang , Andrew Wagenmaker , Kevin Jamieson

We consider a variant of the best arm identification (BAI) problem in multi-armed bandits (MAB) in which there are two sets of arms (source and target), and the objective is to determine the best target arm while only pulling source arms.…

Machine Learning · Computer Science 2021-12-09 Ojash Neopane , Aaditya Ramdas , Aarti Singh

We study the best-arm identification (BAI) problem with a fixed budget and contextual (covariate) information. In each round of an adaptive experiment, after observing contextual information, we choose a treatment arm using past…

Machine Learning · Computer Science 2023-01-05 Masahiro Kato , Masaaki Imaizumi , Takuya Ishihara , Toru Kitagawa

We consider the problem of identifying the best arm in a multi-armed bandit model. Despite a wealth of literature in the traditional fixed budget and fixed confidence regimes of the best arm identification problem, it still remains a…

Machine Learning · Statistics 2025-12-08 Michael O. Harding , Kirthevasan Kandasamy

We consider a novel stochastic multi-armed bandit problem called {\em good arm identification} (GAI), where a good arm is defined as an arm with expected reward greater than or equal to a given threshold. GAI is a pure-exploration problem…

We study best-arm identification in stochastic multi-armed bandits under the fixed-confidence setting, focusing on instances with multiple optimal arms. Unlike prior work that addresses the unknown-number-of-optimal-arms case, we consider…

Machine Learning · Computer Science 2026-03-05 Lan V. Truong

We study the best-arm identification problem in multi-armed bandits with stochastic, potentially private rewards, when the goal is to identify the arm with the highest quantile at a fixed, prescribed level. First, we propose a (non-private)…

Machine Learning · Statistics 2022-12-06 Kontantinos E. Nikolakakis , Dionysios S. Kalogerias , Or Sheffet , Anand D. Sarwate

We study the multi-fidelity multi-armed bandit (MF-MAB), an extension of the canonical multi-armed bandit (MAB) problem. MF-MAB allows each arm to be pulled with different costs (fidelities) and observation accuracy. We study both the best…

Machine Learning · Computer Science 2023-06-14 Xuchuang Wang , Qingyun Wu , Wei Chen , John C. S. Lui

This paper investigates the problem of best arm identification in $\textit{contaminated}$ stochastic multi-arm bandits. In this setting, the rewards obtained from any arm are replaced by samples from an adversarial model with probability…

Machine Learning · Computer Science 2021-11-16 Arpan Mukherjee , Ali Tajer , Pin-Yu Chen , Payel Das

The multi-armed bandit (MAB) problem is a ubiquitous decision-making problem that exemplifies exploration-exploitation tradeoff. Standard formulations exclude risk in decision making. Risknotably complicates the basic reward-maximising…

Machine Learning · Computer Science 2021-05-17 Ming Liang Ang , Eloise Y. Y. Lim , Joel Q. L. Chang

We address the problem of best arm identification (BAI) with a fixed budget for two-armed Gaussian bandits. In BAI, given multiple arms, we aim to find the best arm, an arm with the highest expected reward, through an adaptive experiment.…

Machine Learning · Computer Science 2024-03-19 Masahiro Kato

The multi-armed bandit (MAB) problem is a ubiquitous decision-making problem that exemplifies the exploration-exploitation tradeoff. Standard formulations exclude risk in decision making. Risk notably complicates the basic reward-maximising…

Machine Learning · Computer Science 2021-02-05 Joel Q. L. Chang , Qiuyu Zhu , Vincent Y. F. Tan

We consider the problem of finding, through adaptive sampling, which of $n$ options (arms) has the largest mean. Our objective is to determine a rule which identifies the best arm with a fixed minimum confidence using as few observations as…

Machine Learning · Computer Science 2022-03-17 MohammadJavad Azizi , Sheldon M Ross , Zhengyu Zhang

We consider the best arm identification (BAI) problem in the $K-$armed bandit framework with a modification - the agent is allowed to play a subset of arms at each time slot instead of one arm. Consequently, the agent observes the sample…

Machine Learning · Computer Science 2026-01-30 Siddhartha Parupudi , Gourab Ghatak

Motivated by real-world applications that necessitate responsible experimentation, we introduce the problem of best arm identification (BAI) with minimal regret. This innovative variant of the multi-armed bandit problem elegantly…

Machine Learning · Computer Science 2024-09-30 Junwen Yang , Vincent Y. F. Tan , Tianyuan Jin