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Related papers: Parallelizing Contextual Bandits

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We propose feature perturbation, a simple yet effective exploration strategy for contextual bandits that injects randomness directly into feature inputs, instead of randomizing unknown parameters or adding noise to rewards. Remarkably, this…

Machine Learning · Computer Science 2025-10-27 Seouh-won Yi , Min-hwan Oh

Single-player contextual bandits are a well-studied problem in reinforcement learning that has seen applications in various fields such as advertising, healthcare, and finance. In light of the recent work on \emph{information asymmetric}…

Machine Learning · Computer Science 2025-03-13 William Chang , Yuanhao Lu

We introduce the problem of model selection for contextual bandits, where a learner must adapt to the complexity of the optimal policy while balancing exploration and exploitation. Our main result is a new model selection guarantee for…

Machine Learning · Computer Science 2019-11-15 Dylan J. Foster , Akshay Krishnamurthy , Haipeng Luo

Stochastic linear contextual bandit algorithms have substantial applications in practice, such as recommender systems, online advertising, clinical trials, etc. Recent works show that optimal bandit algorithms are vulnerable to adversarial…

Machine Learning · Statistics 2023-01-31 Qin Ding , Cho-Jui Hsieh , James Sharpnack

We consider a contextual bandit problem with $S$ contexts and $K$ actions. In each round $t=1,2,\dots$, the learner observes a random context and chooses an action based on its past experience. The learner then observes a random reward…

Machine Learning · Computer Science 2023-11-29 Chung-Wei Lee , Qinghua Liu , Yasin Abbasi-Yadkori , Chi Jin , Tor Lattimore , Csaba Szepesvári

This study investigates the problem of $K$-armed linear contextual bandits, an instance of the multi-armed bandit problem, under an adversarial corruption. At each round, a decision-maker observes an independent and identically distributed…

Machine Learning · Computer Science 2023-12-29 Masahiro Kato , Shinji Ito

Contextual multinomial logit (MNL) bandits capture many real-world assortment recommendation problems such as online retailing/advertising. However, prior work has only considered (generalized) linear value functions, which greatly limits…

Machine Learning · Computer Science 2024-02-20 Mengxiao Zhang , Haipeng Luo

In this paper, we propose and study opportunistic contextual bandits - a special case of contextual bandits where the exploration cost varies under different environmental conditions, such as network load or return variation in…

Machine Learning · Computer Science 2019-05-29 Xueying Guo , Xiaoxiao Wang , Xin Liu

The primary goal of my Ph.D. study is to develop provably efficient and practical algorithms for data-driven sequential decision-making under uncertainty. My work focuses on reinforcement learning (RL), multi-armed bandits, and their…

Machine Learning · Computer Science 2025-05-16 Zhiyong Wang

Real-world applications of contextual bandits often exhibit non-stationarity due to seasonality, serendipity, and evolving social trends. While a number of non-stationary contextual bandit learning algorithms have been proposed in the…

Machine Learning · Computer Science 2023-10-17 Zheqing Zhu , Yueyang Liu , Xu Kuang , Benjamin Van Roy

The linear submodular bandit problem was proposed to simultaneously address diversified retrieval and online learning in a recommender system. If there is no uncertainty, this problem is equivalent to a submodular maximization problem under…

Machine Learning · Computer Science 2021-03-30 Sho Takemori , Masahiro Sato , Takashi Sonoda , Janmajay Singh , Tomoko Ohkuma

Contextual bandit algorithms are essential for solving real-world decision making problems. In practice, collecting a contextual bandit's feedback from different domains may involve different costs. For example, measuring drug reaction from…

Machine Learning · Computer Science 2025-04-08 Ziyan Wang , Xiaoming Huo , Hao Wang

We consider the stochastic contextual bandit problem under the high dimensional linear model. We focus on the case where the action space is finite and random, with each action associated with a randomly generated contextual covariate. This…

Machine Learning · Statistics 2020-09-07 Yining Wang , Yi Chen , Ethan X. Fang , Zhaoran Wang , Runze Li

Contextual Bandits is one of the widely popular techniques used in applications such as personalization, recommendation systems, mobile health, causal marketing etc . As a dynamic approach, it can be more efficient than standard A/B testing…

Machine Learning · Computer Science 2022-02-03 Praneet Dutta , Joe Cheuk , Jonathan S Kim , Massimo Mascaro

We propose an extensible deep learning method that uses reinforcement learning to train neural networks for offline ranking in information retrieval (IR). We call our method BanditRank as it treats ranking as a contextual bandit problem. In…

Information Retrieval · Computer Science 2019-10-24 Phanideep Gampa , Sumio Fujita

Large language models (LLMs) exhibit diverse response behaviors, costs, and strengths, making it challenging to select the most suitable LLM for a given user query. We study the problem of adaptive multi-LLM selection in an online setting,…

Machine Learning · Computer Science 2025-06-24 Manhin Poon , XiangXiang Dai , Xutong Liu , Fang Kong , John C. S. Lui , Jinhang Zuo

The contextual multi-armed bandit (MAB) is a widely used framework for problems requiring sequential decision-making under uncertainty, such as recommendation systems. In applications involving a large number of users, the performance of…

Machine Learning · Computer Science 2025-02-05 Zhiyong Wang , Jiahang Sun , Mingze Kong , Jize Xie , Qinghua Hu , John C. S. Lui , Zhongxiang Dai

Most contextual bandit algorithms minimize regret against the best fixed policy, a questionable benchmark for non-stationary environments that are ubiquitous in applications. In this work, we develop several efficient contextual bandit…

Machine Learning · Computer Science 2019-04-05 Haipeng Luo , Chen-Yu Wei , Alekh Agarwal , John Langford

The $K$-armed dueling bandit problem, where the feedback is in the form of noisy pairwise comparisons, has been widely studied. Previous works have only focused on the sequential setting where the policy adapts after every comparison.…

Machine Learning · Computer Science 2022-02-23 Arpit Agarwal , Rohan Ghuge , Viswanath Nagarajan

We study the contextual linear bandit problem, a version of the standard stochastic multi-armed bandit (MAB) problem where a learner sequentially selects actions to maximize a reward which depends also on a user provided per-round context.…

Machine Learning · Computer Science 2018-10-02 Roshan Shariff , Or Sheffet