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Related papers: An Anytime Algorithm for Good Arm Identification

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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 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

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 study best arm identification in a variant of the multi-armed bandit problem where the learner has limited precision in arm selection. The learner can only sample arms via certain exploration bundles, which we refer to as boxes. In…

Machine Learning · Computer Science 2023-05-11 Kota Srinivas Reddy , P. N. Karthik , Nikhil Karamchandani , Jayakrishnan Nair

Good arm identification (GAI) is a pure-exploration bandit problem in which a single learner outputs an arm as soon as it is identified as a good arm. A good arm is defined as an arm with an expected reward greater than or equal to a given…

Machine Learning · Computer Science 2024-03-13 Tzu-Hsien Tsai , Yun-Da Tsai , Shou-De Lin

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 consider the problem of identifying the best arm in stochastic Multi-Armed Bandits (MABs) using a fixed sampling budget. Characterizing the minimal instance-specific error probability for this problem constitutes one of the important…

Machine Learning · Computer Science 2024-02-21 Po-An Wang , Ruo-Chun Tzeng , Alexandre Proutiere

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

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 consider fixed-budget best-arm identification in two-armed Gaussian bandit problems. One of the longstanding open questions is the existence of an optimal strategy under which the probability of misidentification matches a lower bound.…

Machine Learning · Statistics 2023-01-02 Masahiro Kato , Kaito Ariu , Masaaki Imaizumi , Masahiro Nomura , Chao Qin

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

We propose a new strategy for best-arm identification with fixed confidence of Gaussian variables with bounded means and unit variance. This strategy, called Exploration-Biased Sampling, is not only asymptotically optimal: it is to the best…

Statistics Theory · Mathematics 2022-03-08 Antoine Barrier , Aurélien Garivier , Tomáš Kocák

We study the batched best arm identification (BBAI) problem, where the learner's goal is to identify the best arm while switching the policy as less as possible. In particular, we aim to find the best arm with probability $1-\delta$ for…

Machine Learning · Computer Science 2025-03-05 Tianyuan Jin , Yu Yang , Jing Tang , Xiaokui Xiao , Pan Xu

We present an efficient and generalised procedure to accurately identify the best (or near best) performing algorithm for each sub-task in a multi-problem domain. Our approach treats this as a set of best arm identification problems for…

Machine Learning · Computer Science 2026-04-22 Matthew Stephenson , Alex Newcombe , Eric Piette , Dennis Soemers

In fixed budget bandit identification, an algorithm sequentially observes samples from several distributions up to a given final time. It then answers a query about the set of distributions. A good algorithm will have a small probability of…

Machine Learning · Statistics 2023-07-03 Rémy Degenne

We study the problem of best arm identification in linear bandits in the fixed-budget setting. By leveraging properties of the G-optimal design and incorporating it into the arm allocation rule, we design a parameter-free algorithm, Optimal…

Machine Learning · Computer Science 2022-09-22 Junwen Yang , Vincent Y. F. Tan

We consider the problem of identifying any $k$ out of the best $m$ arms in an $n$-armed stochastic multi-armed bandit. Framed in the PAC setting, this particular problem generalises both the problem of `best subset selection' and that of…

Machine Learning · Computer Science 2019-01-25 Arghya Roy Chaudhuri , Shivaram Kalyanakrishnan

This study investigates the experimental design problem for identifying the arm with the highest expected outcome, referred to as best arm identification (BAI). In our experiments, the number of treatment-allocation rounds is fixed. During…

Statistics Theory · Mathematics 2024-03-12 Masahiro Kato

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

Stochastic Rising Bandits (SRBs) model sequential decision-making problems in which the expected reward of the available options increases every time they are selected. This setting captures a wide range of scenarios in which the available…

Machine Learning · Computer Science 2024-05-29 Marco Mussi , Alessandro Montenegro , Francesco Trovó , Marcello Restelli , Alberto Maria Metelli