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Related papers: Stochastic Bandits with Context Distributions

200 papers

We propose a new sequential decision-making setting, combining key aspects of two established online learning problems with bandit feedback. The optimal action to play at any given moment is contingent on an underlying changing state which…

Machine Learning · Computer Science 2023-11-07 Alexander Galozy , Slawomir Nowaczyk , Mattias Ohlsson

In many real-world sequential decision-making problems, an action does not immediately reflect on the feedback and spreads its effects over a long time frame. For instance, in online advertising, investing in a platform produces an…

Machine Learning · Computer Science 2023-05-31 Marco Mussi , Alberto Maria Metelli , Marcello Restelli

We introduce a new model of stochastic bandits with adversarial corruptions which aims to capture settings where most of the input follows a stochastic pattern but some fraction of it can be adversarially changed to trick the algorithm,…

Machine Learning · Computer Science 2018-03-28 Thodoris Lykouris , Vahab Mirrokni , Renato Paes Leme

Contextual bandit algorithms -- a class of multi-armed bandit algorithms that exploit the contextual information -- have been shown to be effective in solving sequential decision making problems under uncertainty. A common assumption…

Machine Learning · Computer Science 2017-01-25 Linqi Song , Jie Xu

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 stochastic non-stationary linear bandits where the linear parameter connecting contexts to the reward changes over time. Existing algorithms in this setting localize the policy by gradually discarding or down-weighting past…

Machine Learning · Statistics 2026-03-05 Margherita Lazzaretto , Jonas Peters , Niklas Pfister

This paper studies semiparametric contextual bandits, a generalization of the linear stochastic bandit problem where the reward for an action is modeled as a linear function of known action features confounded by an non-linear…

Machine Learning · Statistics 2018-07-17 Akshay Krishnamurthy , Zhiwei Steven Wu , Vasilis Syrgkanis

We consider an online decision making setting known as contextual bandit problem, and propose an approach for improving contextual bandit performance by using an adaptive feature extraction (representation learning) based on online…

Artificial Intelligence · Computer Science 2020-09-15 Baihan Lin , Djallel Bouneffouf , Guillermo Cecchi , Irina Rish

This paper considers stochastic bandits with side observations, a model that accounts for both the exploration/exploitation dilemma and relationships between arms. In this setting, after pulling an arm i, the decision maker also observes…

Machine Learning · Computer Science 2012-10-19 Stephane Caron , Branislav Kveton , Marc Lelarge , Smriti Bhagat

Contextual bandits serve as a fundamental model for many sequential decision making tasks. The most popular theoretically justified approaches are based on the optimism principle. While these algorithms can be practical, they are known to…

Machine Learning · Computer Science 2020-03-17 Botao Hao , Tor Lattimore , Csaba Szepesvari

Bandit learning is characterized by the tension between long-term exploration and short-term exploitation. However, as has recently been noted, in settings in which the choices of the learning algorithm correspond to important decisions…

Machine Learning · Computer Science 2018-01-11 Sampath Kannan , Jamie Morgenstern , Aaron Roth , Bo Waggoner , Zhiwei Steven Wu

We study stage-wise conservative linear stochastic bandits: an instance of bandit optimization, which accounts for (unknown) safety constraints that appear in applications such as online advertising and medical trials. At each stage, the…

Machine Learning · Computer Science 2020-10-02 Ahmadreza Moradipari , Christos Thrampoulidis , Mahnoosh Alizadeh

We study sequential decision making in environments where rewards are only partially observed, but can be modeled as a function of observed contexts and the chosen action by the decision maker. This setting, known as contextual bandits,…

Methodology · Statistics 2015-03-11 Miroslav Dudík , Dumitru Erhan , John Langford , Lihong Li

We consider the problem of model selection for the general stochastic contextual bandits under the realizability assumption. We propose a successive refinement based algorithm called Adaptive Contextual Bandit ({\ttfamily ACB}), that works…

Machine Learning · Statistics 2023-07-21 Avishek Ghosh , Abishek Sankararaman , Kannan Ramchandran

We study a collaborative multi-agent stochastic linear bandit setting, where $N$ agents that form a network communicate locally to minimize their overall regret. In this setting, each agent has its own linear bandit problem (its own reward…

Machine Learning · Computer Science 2022-05-16 Ahmadreza Moradipari , Mohammad Ghavamzadeh , Mahnoosh Alizadeh

Information is often stored in a distributed and proprietary form, and agents who own information are often self-interested and require incentives to reveal their information. Suitable mechanisms are required to elicit and aggregate such…

Multiagent Systems · Computer Science 2022-12-02 Wenlong Wang , Thomas Pfeiffer

The contextual bandit problem, where agents arrive sequentially with personal contexts and the system adapts its arm allocation decisions accordingly, has recently garnered increasing attention for enabling more personalized outcomes.…

Machine Learning · Computer Science 2025-05-06 Yiting Hu , Lingjie Duan

In the stochastic contextual bandit setting, regret-minimizing algorithms have been extensively researched, but their instance-minimizing best-arm identification counterparts remain seldom studied. In this work, we focus on the stochastic…

Machine Learning · Statistics 2023-10-04 Zhaoqi Li , Lillian Ratliff , Houssam Nassif , Kevin Jamieson , Lalit Jain

Classic contextual bandit algorithms for linear models, such as LinUCB, assume that the reward distribution for an arm is modeled by a stationary linear regression. When the linear regression model is non-stationary over time, the regret of…

Machine Learning · Statistics 2020-02-14 Qin Ding , Cho-Jui Hsieh , James Sharpnack

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