English
Related papers

Related papers: Selective Sampling for Online Best-arm Identificat…

200 papers

This paper studies active learning in the context of robust statistics. Specifically, we propose a variant of the Best Arm Identification problem for \emph{contaminated bandits}, where each arm pull has probability $\varepsilon$ of…

Statistics Theory · Mathematics 2021-11-16 Jason Altschuler , Victor-Emmanuel Brunel , Alan Malek

We investigate the sample complexity of learning the optimal arm for multi-task bandit problems. Arms consist of two components: one that is shared across tasks (that we call representation) and one that is task-specific (that we call…

Machine Learning · Statistics 2022-11-29 Alessio Russo , Alexandre Proutiere

The question of selecting the "best" amongst different choices is a common problem in statistics. In drug development, our motivating setting, the question becomes, for example: what is the dose that gives me a pre-specified risk of…

Statistics Theory · Mathematics 2018-03-15 Pavel Mozgunov , Thomas Jaki

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 study the best-arm identification problem in linear bandit, where the rewards of the arms depend linearly on an unknown parameter $\theta^*$ and the objective is to return the arm with the largest reward. We characterize the complexity…

Machine Learning · Computer Science 2014-11-05 Marta Soare , Alessandro Lazaric , Rémi Munos

We study the problem of identifying the best arm in a multi-armed bandit environment when each arm is a time-homogeneous and ergodic discrete-time Markov process on a common, finite state space. The state evolution on each arm is governed…

Machine Learning · Statistics 2022-03-30 P. N. Karthik , Kota Srinivas Reddy , Vincent Y. F. Tan

We study the problem of best arm identification in linearly parameterised multi-armed bandits. Given a set of feature vectors $\mathcal{X}\subset\mathbb{R}^d,$ a confidence parameter $\delta$ and an unknown vector $\theta^*,$ the goal is to…

Machine Learning · Computer Science 2020-06-16 Mohammadi Zaki , Avi Mohan , Aditya Gopalan

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 investigate the fixed-budget best-arm identification (BAI) problem for linear bandits in a potentially non-stationary environment. Given a finite arm set $\mathcal{X}\subset\mathbb{R}^d$, a fixed budget $T$, and an unpredictable sequence…

Machine Learning · Computer Science 2024-02-16 Zhihan Xiong , Romain Camilleri , Maryam Fazel , Lalit Jain , Kevin Jamieson

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

This paper studies two variants of the best arm identification (BAI) problem under the streaming model, where we have a stream of $n$ arms with reward distributions supported on $[0,1]$ with unknown means. The arms in the stream are…

Machine Learning · Computer Science 2024-10-24 Tianyuan Jin , Keke Huang , Jing Tang , Xiaokui Xiao

The performance of a machine learning system is usually evaluated by using i.i.d.\ observations with true labels. However, acquiring ground truth labels is expensive, while obtaining unlabeled samples may be cheaper. Stratified sampling can…

Machine Learning · Computer Science 2019-07-29 Tiancheng Yu , Xiyu Zhai , Suvrit Sra

Top Two algorithms arose as an adaptation of Thompson sampling to best arm identification in multi-armed bandit models (Russo, 2016), for parametric families of arms. They select the next arm to sample from by randomizing among two…

Machine Learning · Statistics 2022-10-05 Marc Jourdan , Rémy Degenne , Dorian Baudry , Rianne de Heide , Emilie Kaufmann

Active learning methods have shown great promise in reducing the number of samples necessary for learning. As automated learning systems are adopted into real-time, real-world decision-making pipelines, it is increasingly important that…

Machine Learning · Computer Science 2022-06-23 Romain Camilleri , Andrew Wagenmaker , Jamie Morgenstern , Lalit Jain , Kevin Jamieson

In pure-exploration problems, information is gathered sequentially to answer a question on the stochastic environment. While best-arm identification for linear bandits has been extensively studied in recent years, few works have been…

Machine Learning · Statistics 2022-06-10 Marc Jourdan , Rémy Degenne

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

This study investigates minimax and Bayes optimal strategies for fixed-budget best-arm identification. We consider an adaptive procedure consisting of a sampling phase followed by a recommendation phase, and we design an adaptive experiment…

Econometrics · Economics 2026-02-05 Masahiro Kato

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

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 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