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Related papers: Optimal Best-Arm Identification under Fixed Confid…

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We give a new algorithm for best arm identification in linearly parameterised bandits in the fixed confidence setting. The algorithm generalises the well-known LUCB algorithm of Kalyanakrishnan et al. (2012) by playing an arm which…

Machine Learning · Computer Science 2019-11-11 Mohammadi Zaki , Avinash Mohan , Aditya Gopalan

We consider the fixed-confidence best arm identification (FC-BAI) problem in the Bayesian setting. This problem aims to find the arm of the largest mean with a fixed confidence level when the bandit model has been sampled from the known…

Machine Learning · Statistics 2024-06-25 Kyoungseok Jang , Junpei Komiyama , Kazutoshi Yamazaki

We consider the best arm identification problem, where the goal is to identify the arm with the highest mean reward from a set of $K$ arms under a limited sampling budget. This problem models many practical scenarios such as A/B testing. We…

Machine Learning · Statistics 2026-05-05 Junpei Komiyama , Kyoungseok Jang , Junya Honda

We study fixed-confidence best arm identification in generalized linear bandits under a hybrid feedback model: at each round, the learner may query either (i) absolute reward feedback from a single arm or (ii) relative (dueling) feedback…

Artificial Intelligence · Computer Science 2026-05-08 Qirun Zeng , Xuchuang Wang , Jiayi Shen , Xutong Liu , Fang Kong , Jinhang Zuo

We consider a stochastic bandit problem with a possibly infinite number of arms. We write $p^*$ for the proportion of optimal arms and $\Delta$ for the minimal mean-gap between optimal and sub-optimal arms. We characterize the optimal…

Machine Learning · Computer Science 2021-11-08 Rianne de Heide , James Cheshire , Pierre Ménard , Alexandra Carpentier

We study the best-arm identification problem with fixed confidence when contextual (covariate) information is available in stochastic bandits. Although we can use contextual information in each round, we are interested in the marginalized…

Machine Learning · Computer Science 2024-02-27 Masahiro Kato , Kaito Ariu

Decision making under uncertain environments in the maximization of expected reward while minimizing its risk is one of the ubiquitous problems in many subjects. Here, we introduce a novel problem setting in stochastic bandit optimization…

Machine Learning · Computer Science 2025-10-27 Shunta Nonaga , Koji Tabata , Yuta Mizuno , Tamiki Komatsuzaki

We study best arm identification in a federated multi-armed bandit setting with a central server and multiple clients, when each client has access to a {\em subset} of arms and each arm yields independent Gaussian observations. The goal is…

Machine Learning · Computer Science 2023-12-20 Zhirui Chen , P. N. Karthik , Vincent Y. F. Tan , Yeow Meng Chee

We study a grouped bandit setting where each arm comprises multiple independent sub-arms referred to as attributes. Each attribute of each arm has an independent stochastic reward. We impose the constraint that for an arm to be deemed…

Machine Learning · Computer Science 2024-12-12 Sahil Dharod , Malyala Preethi Sravani , Sakshi Heda , Sharayu Moharir

The best arm identification problem (BEST-1-ARM) is the most basic pure exploration problem in stochastic multi-armed bandits. The problem has a long history and attracted significant attention for the last decade. However, we do not yet…

Machine Learning · Computer Science 2016-05-30 Lijie Chen , Jian Li

We consider the problem of \textit{best arm identification} with a \textit{fixed budget $T$}, in the $K$-armed stochastic bandit setting, with arms distribution defined on $[0,1]$. We prove that any bandit strategy, for at least one bandit…

Machine Learning · Statistics 2016-05-31 Alexandra Carpentier , Andrea Locatelli

The best arm identification problem requires identifying the best alternative (i.e., arm) in active experimentation using the smallest number of experiments (i.e., arm pulls), which is crucial for cost-efficient and timely decision-making…

Machine Learning · Computer Science 2025-06-17 Kapilan Balagopalan , Tuan Ngo Nguyen , Yao Zhao , Kwang-Sung Jun

We study the fixed-budget best-arm identification (BAI) problem in non-stationary linear bandits. Concretely, given a fixed time budget $T\in \mathbb{N}$, finite arm set $\mathcal{X} \subset \mathbb{R}^d$, and a potentially adversarial…

Machine Learning · Statistics 2026-03-12 Leo Maynard-Zhang , Zhihan Xiong , Kevin Jamieson , Maryam Fazel

We consider a variant of the best arm identification task in stochastic multi-armed bandits. Motivated by risk-averse decision-making problems, our goal is to identify a set of $m$ arms with the highest $\tau$-quantile values within a fixed…

Machine Learning · Computer Science 2023-02-22 Mengyan Zhang , Cheng Soon Ong

We consider the problem of the best arm identification in the presence of stochastic constraints, where there is a finite number of arms associated with multiple performance measures. The goal is to identify the arm that optimizes the…

Machine Learning · Computer Science 2025-01-08 Le Yang , Siyang Gao , Cheng Li , Yi Wang

In pure exploration problems, a statistician sequentially collects information to answer a question about some stochastic and unknown environment. The probability of returning a wrong answer should not exceed a maximum risk parameter…

Machine Learning · Computer Science 2026-02-19 Riccardo Poiani , Martino Bernasconi , Andrea Celli

The challenge of identifying the best feasible arm within a fixed budget has attracted considerable interest in recent years. However, a notable gap remains in the literature: the exact exponential rate at which the error probability…

Machine Learning · Computer Science 2025-06-04 Jie Bian , Vincent Y. F. Tan

We study the fixed-confidence best arm identification (BAI) problem within the multi-armed bandit (MAB) framework under the Entropic Value-at-Risk (EVaR) criterion. Our analysis considers a nonparametric setting, allowing for general reward…

Machine Learning · Computer Science 2025-10-07 Mehrasa Ahmadipour , Aurélien Garivier

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

We investigate an active pure-exploration setting, that includes best-arm identification, in the context of linear stochastic bandits. While asymptotically optimal algorithms exist for standard multi-arm bandits, the existence of such…

Machine Learning · Statistics 2020-07-03 Rémy Degenne , Pierre Ménard , Xuedong Shang , Michal Valko