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Related papers: Non-stochastic Bandits With Evolving Observations

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We study bandit model selection in stochastic environments. Our approach relies on a meta-algorithm that selects between candidate base algorithms. We develop a meta-algorithm-base algorithm abstraction that can work with general classes of…

Machine Learning · Computer Science 2022-12-06 Aldo Pacchiano , My Phan , Yasin Abbasi-Yadkori , Anup Rao , Julian Zimmert , Tor Lattimore , Csaba Szepesvari

We consider the problem of stochastic $K$-armed dueling bandit in the contextual setting, where at each round the learner is presented with a context set of $K$ items, each represented by a $d$-dimensional feature vector, and the goal of…

Machine Learning · Computer Science 2021-05-11 Aadirupa Saha , Aditya Gopalan

We study the linear bandit problem that accounts for partially observable features. Without proper handling, unobserved features can lead to linear regret in the decision horizon $T$, as their influence on rewards is unknown. To tackle this…

Machine Learning · Statistics 2025-08-19 Wonyoung Kim , Sungwoo Park , Garud Iyengar , Assaf Zeevi , Min-hwan Oh

In this paper, we investigate the existence of online learning algorithms with bandit feedback that simultaneously guarantee $O(1)$ regret compared to a given comparator strategy, and $\tilde{O}(\sqrt{T})$ regret compared to any fixed…

Machine Learning · Computer Science 2025-06-05 Adrian Müller , Jon Schneider , Stratis Skoulakis , Luca Viano , Volkan Cevher

We consider a special case of bandit problems, named batched bandits, in which an agent observes batches of responses over a certain time period. Unlike previous work, we consider a more practically relevant batch-centric scenario of batch…

Machine Learning · Computer Science 2023-04-04 Danil Provodin , Pratik Gajane , Mykola Pechenizkiy , Maurits Kaptein

The problem of bandit with graph feedback generalizes both the multi-armed bandit (MAB) problem and the learning with expert advice problem by encoding in a directed graph how the loss vector can be observed in each round of the game. The…

Machine Learning · Computer Science 2023-08-07 Yuchen He , Chihao Zhang

We consider the problem of learning personalized decision policies from observational bandit feedback data across multiple heterogeneous data sources. In our approach, we introduce a novel regret analysis that establishes finite-sample…

Machine Learning · Computer Science 2024-10-14 Aldo Gael Carranza , Susan Athey

We revisit the problem of online learning with sleeping experts/bandits: in each time step, only a subset of the actions are available for the algorithm to choose from (and learn about). The work of Kleinberg et al. (2010) showed that there…

Machine Learning · Computer Science 2021-04-27 Ehsan Emamjomeh-Zadeh , Chen-Yu Wei , Haipeng Luo , David Kempe

Bandits with feedback graphs are powerful online learning models that interpolate between the full information and classic bandit problems, capturing many real-life applications. A recent work by Zhang et al. (2023) studies the contextual…

Machine Learning · Computer Science 2024-02-14 Mengxiao Zhang , Yuheng Zhang , Haipeng Luo , Paul Mineiro

We introduce a novel algorithmic approach to content recommendation based on adaptive clustering of exploration-exploitation ("bandit") strategies. We provide a sharp regret analysis of this algorithm in a standard stochastic noise setting,…

Machine Learning · Computer Science 2014-06-09 Claudio Gentile , Shuai Li , Giovanni Zappella

Contextual bandit algorithms are sensitive to the estimation method of the outcome model as well as the exploration method used, particularly in the presence of rich heterogeneity or complex outcome models, which can lead to difficult…

Machine Learning · Statistics 2018-12-18 Maria Dimakopoulou , Zhengyuan Zhou , Susan Athey , Guido Imbens

We consider the problem where M agents collaboratively interact with an instance of a stochastic K-armed contextual bandit, where K>>M. The goal of the agents is to simultaneously minimize the cumulative regret over all the agents over a…

Machine Learning · Computer Science 2022-11-16 Jiabin Lin , Shana Moothedath

We study nonstochastic bandits and experts in a delayed setting where delays depend on both time and arms. While the setting in which delays only depend on time has been extensively studied, the arm-dependent delay setting better captures…

Machine Learning · Computer Science 2021-12-22 Dirk van der Hoeven , Nicolò Cesa-Bianchi

Online model selection in Bayesian bandits raises a fundamental exploration challenge: When an environment instance is sampled from a prior distribution, how can we design an adaptive strategy that explores multiple bandit learners and…

Machine Learning · Computer Science 2026-02-23 Aida Afshar , Yuke Zhang , Aldo Pacchiano

We study adaptive regret bounds in terms of the variation of the losses (the so-called path-length bounds) for both multi-armed bandit and more generally linear bandit. We first show that the seemingly suboptimal path-length bound of (Wei…

Machine Learning · Computer Science 2019-06-19 Sébastien Bubeck , Yuanzhi Li , Haipeng Luo , Chen-Yu Wei

We introduce a new stochastic smoothing perspective to study adversarial contextual bandit problems. We propose a general algorithm template that represents random perturbation based algorithms and identify several perturbation…

Machine Learning · Statistics 2019-06-12 Young Hun Jung , Ambuj Tewari

Regret bounds in online learning compare the player's performance to $L^*$, the optimal performance in hindsight with a fixed strategy. Typically such bounds scale with the square root of the time horizon $T$. The more refined concept of…

Machine Learning · Computer Science 2018-02-12 Zeyuan Allen-Zhu , Sébastien Bubeck , Yuanzhi Li

We study the $K$-armed contextual dueling bandit problem, a sequential decision making setting in which the learner uses contextual information to make two decisions, but only observes \emph{preference-based feedback} suggesting that one…

Machine Learning · Computer Science 2021-11-25 Aadirupa Saha , Akshay Krishnamurthy

We study the problem of information sharing and cooperation in Multi-Player Multi-Armed bandits. We propose the first algorithm that achieves logarithmic regret for this problem when the collision reward is unknown. Our results are based on…

Machine Learning · Computer Science 2022-10-04 Aldo Pacchiano , Peter Bartlett , Michael I. Jordan

We address online learning in complex auction settings, such as sponsored search auctions, where the value of the bidder is unknown to her, evolving in an arbitrary manner and observed only if the bidder wins an allocation. We leverage the…

Computer Science and Game Theory · Computer Science 2018-06-04 Zhe Feng , Chara Podimata , Vasilis Syrgkanis