English
Related papers

Related papers: Generalized Neyman Allocation for Locally Minimax …

200 papers

This paper investigates a hitherto unaddressed aspect of best arm identification (BAI) in stochastic multi-armed bandits in the fixed-confidence setting. Two key metrics for assessing bandit algorithms are computational efficiency and…

Machine Learning · Statistics 2023-06-26 Arpan Mukherjee , Ali Tajer

We consider a multi-armed bandit setting with finitely many arms, in which each arm yields an $M$-dimensional vector reward upon selection. We assume that the reward of each dimension (a.k.a. {\em objective}) is generated independently of…

Machine Learning · Computer Science 2025-01-24 Zhirui Chen , P. N. Karthik , Yeow Meng Chee , Vincent Y. F. Tan

We consider the fixed-budget best arm identification problem where the goal is to find the arm of the largest mean with a fixed number of samples. It is known that the probability of misidentifying the best arm is exponentially small to the…

Machine Learning · Statistics 2022-10-28 Junpei Komiyama , Taira Tsuchiya , Junya Honda

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…

In this paper, we introduce a multi-armed bandit problem termed max-min grouped bandits, in which the arms are arranged in possibly-overlapping groups, and the goal is to find the group whose worst arm has the highest mean reward. This…

Machine Learning · Statistics 2022-03-16 Zhenlin Wang , Jonathan Scarlett

We study best-arm identification with fixed confidence in bandit models with graph smoothness constraint. We provide and analyze an efficient gradient ascent algorithm to compute the sample complexity of this problem as a solution of a…

Machine Learning · Computer Science 2020-05-21 Tomáš Kocák , Aurélien Garivier

We consider best arm identification in the multi-armed bandit problem. Assuming certain continuity conditions of the prior, we characterize the rate of the Bayesian simple regret. Differing from Bayesian regret minimization (Lai, 1987), the…

Machine Learning · Computer Science 2023-07-27 Junpei Komiyama , Kaito Ariu , Masahiro Kato , Chao Qin

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

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

In bandit best-arm identification, an algorithm is tasked with finding the arm with highest mean reward with a specified accuracy as fast as possible. We study multi-fidelity best-arm identification, in which the algorithm can choose to…

Machine Learning · Computer Science 2025-05-27 Riccardo Poiani , Rémy Degenne , Emilie Kaufmann , Alberto Maria Metelli , Marcello Restelli

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

We study the fixed-confidence best-arm identification problem in unimodal bandits, in which the means of the arms increase with the index of the arm up to their maximum, then decrease. We derive two lower bounds on the stopping time of any…

Machine Learning · Computer Science 2025-05-27 Riccardo Poiani , Marc Jourdan , Emilie Kaufmann , Rémy Degenne

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 focuses on selecting the arm with the highest variance from a set of $K$ independent arms. Specifically, we focus on two settings: (i) misallocation minimization setting, that penalizes the number of pulls of suboptimal arms in…

Machine Learning · Computer Science 2026-02-18 Sabrina Khurshid , Gourab Ghatak , Mohammad Shahid Abdulla

We study the problem of Bayesian fixed-budget best-arm identification (BAI) in structured bandits. We propose an algorithm that uses fixed allocations based on the prior information and the structure of the environment. We provide…

Machine Learning · Statistics 2025-04-28 Nicolas Nguyen , Imad Aouali , András György , Claire Vernade

We study fixed-confidence Best Arm Identification (BAI) in semiparametric bandits, where rewards are linear in arm features plus an unknown additive baseline shift. Unlike linear-bandit BAI, this setting requires orthogonalized regression,…

Machine Learning · Statistics 2026-04-07 Seok-Jin Kim

Top-$2$ methods have become popular in solving the best arm identification (BAI) problem. The best arm, or the arm with the largest mean amongst finitely many, is identified through an algorithm that at any sequential step independently…

Machine Learning · Computer Science 2024-12-17 Agniv Bandyopadhyay , Sandeep Juneja , Shubhada Agrawal

We study the problem of best-arm identification with fixed confidence in stochastic linear bandits. The objective is to identify the best arm with a given level of certainty while minimizing the sampling budget. We devise a simple algorithm…

Machine Learning · Statistics 2020-06-30 Yassir Jedra , Alexandre Proutiere

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 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