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Related papers: Doubly High-Dimensional Contextual Bandits: An Int…

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In a multi-armed bandit (MAB) problem, an online algorithm makes a sequence of choices. In each round it chooses from a time-invariant set of alternatives and receives the payoff associated with this alternative. While the case of small…

Data Structures and Algorithms · Computer Science 2014-05-21 Aleksandrs Slivkins

We consider a bandit problem which involves sequential sampling from two populations (arms). Each arm produces a noisy reward realization which depends on an observable random covariate. The goal is to maximize cumulative expected reward.…

Statistics Theory · Mathematics 2010-03-09 Philippe Rigollet , Assaf Zeevi

We consider the stochastic linear (multi-armed) contextual bandit problem with the possibility of hidden simple multi-armed bandit structure in which the rewards are independent of the contextual information. Algorithms that are designed…

Machine Learning · Statistics 2020-10-07 Niladri S. Chatterji , Vidya Muthukumar , Peter L. Bartlett

Ranking algorithms are fundamental to various online platforms across e-commerce sites to content streaming services. Our research addresses the challenge of adaptively ranking items from a candidate pool for heterogeneous users, a key…

Machine Learning · Computer Science 2024-06-10 Jingyuan Wang , Perry Dong , Ying Jin , Ruohan Zhan , Zhengyuan Zhou

This paper presents a class of Dynamic Multi-Armed Bandit problems where the reward can be modeled as the noisy output of a time varying linear stochastic dynamic system that satisfies some boundedness constraints. The class allows many…

Machine Learning · Computer Science 2017-10-10 T. W. U. Madhushani , D. H. S. Maithripala , N. E. Leonard

We study a nonparametric contextual bandit problem where the expected reward functions belong to a H\"older class with smoothness parameter $\beta$. We show how this interpolates between two extremes that were previously studied in…

Machine Learning · Statistics 2020-09-14 Yichun Hu , Nathan Kallus , Xiaojie Mao

In the classical multi-armed bandit problem, instance-dependent algorithms attain improved performance on "easy" problems with a gap between the best and second-best arm. Are similar guarantees possible for contextual bandits? While…

Machine Learning · Computer Science 2020-10-08 Dylan J. Foster , Alexander Rakhlin , David Simchi-Levi , Yunzong Xu

In this paper we consider the adversarial contextual bandit problem in metric spaces. The paper "Nearest neighbour with bandit feedback" tackled this problem but when there are many contexts near the decision boundary of the comparator…

Machine Learning · Computer Science 2023-12-18 Stephen Pasteris , Chris Hicks , Vasilios Mavroudis

Contextual bandit learning is increasingly favored in modern large-scale recommendation systems. To better utlize the contextual information and available user or item features, the integration of neural networks have been introduced to…

Machine Learning · Computer Science 2024-06-05 Hongbo Guo , Zheqing Zhu

We study constrained contextual bandits (CCB) with adversarially chosen contexts, where each action yields a random reward and incurs a random cost. We adopt the standard realizability assumption: conditioned on the observed context,…

Machine Learning · Computer Science 2026-02-06 Dhruv Sarkar , Abhishek Sinha

We study the ranking problem in generalized linear bandits. At each time, the learning agent selects an ordered list of items and observes stochastic outcomes. In recommendation systems, displaying an ordered list of the most attractive…

Machine Learning · Statistics 2024-01-03 Amitis Shidani , George Deligiannidis , Arnaud Doucet

Causal bandit is a nascent learning model where an agent sequentially experiments in a causal network of variables, in order to identify the reward-maximizing intervention. Despite the model's wide applicability, existing analytical results…

Machine Learning · Statistics 2021-03-09 Ruiyang Song , Stefano Rini , Kuang Xu

We study repeated bilateral trade when the valuations of the sellers and the buyers are contextual. More precisely, the agents' valuations are given by the inner product of a context vector with two unknown $d$-dimensional vectors -- one…

Computer Science and Game Theory · Computer Science 2026-02-16 Romain Cosson , Federico Fusco , Anupam Gupta , Stefano Leonardi , Renato Paes Leme , Matteo Russo

We study here the problem of learning the exploration exploitation trade-off in the contextual bandit problem with linear reward function setting. In the traditional algorithms that solve the contextual bandit problem, the exploration is a…

Machine Learning · Computer Science 2020-05-06 Djallel Bouneffouf , Emmanuelle Claeys

In many web applications, a recommendation is not a single item suggested to a user but a list of possibly interesting contents that may be ranked in some contexts. The combinatorial bandit problem has been studied quite extensively these…

Data Structures and Algorithms · Computer Science 2016-05-27 Hossein Vahabi , Paul Lagrée , Claire Vernade , Olivier Cappé

In real-world streaming recommender systems, user preferences often dynamically change over time (e.g., a user may have different preferences during weekdays and weekends). Existing bandit-based streaming recommendation models only consider…

Information Retrieval · Computer Science 2023-08-17 Chenglei Shen , Xiao Zhang , Wei Wei , Jun Xu

A challenging aspect of the bandit problem is that a stochastic reward is observed only for the chosen arm and the rewards of other arms remain missing. The dependence of the arm choice on the past context and reward pairs compounds the…

Machine Learning · Statistics 2023-05-02 Wonyoung Kim , Gi-soo Kim , Myunghee Cho Paik

We present a new algorithm for the contextual bandit learning problem, where the learner repeatedly takes one of $K$ actions in response to the observed context, and observes the reward only for that chosen action. Our method assumes access…

Machine Learning · Computer Science 2014-10-15 Alekh Agarwal , Daniel Hsu , Satyen Kale , John Langford , Lihong Li , Robert E. Schapire

Recommender systems are a ubiquitous feature of online platforms. Increasingly, they are explicitly tasked with increasing users' long-term satisfaction. In this context, we study a content exploration task, which we formalize as a…

Machine Learning · Computer Science 2023-07-21 Thomas M. McDonald , Lucas Maystre , Mounia Lalmas , Daniel Russo , Kamil Ciosek

Personalization is a crucial aspect of many online experiences. In particular, content ranking is often a key component in delivering sophisticated personalization results. Commonly, supervised learning-to-rank methods are applied, which…

Machine Learning · Computer Science 2020-04-29 Beyza Ermis , Patrick Ernst , Yannik Stein , Giovanni Zappella