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Related papers: Policy Gradients for Contextual Recommendations

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In many applications, e.g. in healthcare and e-commerce, the goal of a contextual bandit may be to learn an optimal treatment assignment policy at the end of the experiment. That is, to minimize simple regret. However, this objective…

Machine Learning · Computer Science 2023-11-06 Sanath Kumar Krishnamurthy , Ruohan Zhan , Susan Athey , Emma Brunskill

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

In this paper, we address the stochastic contextual linear bandit problem, where a decision maker is provided a context (a random set of actions drawn from a distribution). The expected reward of each action is specified by the inner…

Machine Learning · Statistics 2023-05-30 Osama A. Hanna , Lin F. Yang , Christina Fragouli

Contextual Bandit (CB) algorithms are widely adopted for personalized recommendations but often struggle in dynamic environments typical of fantasy sports, where rapid changes in user behavior and dramatic shifts in reward distributions due…

Machine Learning · Computer Science 2026-01-22 Anupam Agrawal , Rajesh Mohanty , Shamik Bhattacharjee , Abhimanyu Mittal

Over the past decade, contextual bandit algorithms have been gaining in popularity due to their effectiveness and flexibility in solving sequential decision problems---from online advertising and finance to clinical trial design and…

Machine Learning · Computer Science 2020-01-03 Robin van Emden , Maurits Kaptein

The contextual bandit has been identified as a powerful framework to formulate the recommendation process as a sequential decision-making process, where each item is regarded as an arm and the objective is to minimize the regret of $T$…

Machine Learning · Computer Science 2024-09-30 Yikun Ban , Yunzhe Qi , Tianxin Wei , Lihui Liu , Jingrui He

For a real-world decision-making problem, the reward function often needs to be engineered or learned. A popular approach is to utilize human feedback to learn a reward function for training. The most straightforward way to do so is to ask…

Machine Learning · Computer Science 2023-10-31 Xiang Ji , Huazheng Wang , Minshuo Chen , Tuo Zhao , Mengdi Wang

We study online learning in contextual pay-per-click auctions where at each of the $T$ rounds, the learner receives some context along with a set of ads and needs to make an estimate on their click-through rate (CTR) in order to run a…

Machine Learning · Computer Science 2023-10-10 Mengxiao Zhang , Haipeng Luo

Contextual bandit algorithms are essential for solving many real-world interactive machine learning problems. Despite multiple recent successes on statistically and computationally efficient methods, the practical behavior of these…

Machine Learning · Statistics 2021-06-08 Alberto Bietti , Alekh Agarwal , John Langford

Solutions to address the periodic review inventory control problem with nonstationary random demand, lost sales, and stochastic vendor lead times typically involve making strong assumptions on the dynamics for either approximation or…

Machine Learning · Statistics 2023-10-26 Dean Foster , Randy Jia , Dhruv Madeka

Offline contextual bandits allow one to learn policies from historical/offline data without requiring online interaction. However, offline policy optimization that maximizes overall expected rewards can unintentionally amplify the reward…

Machine Learning · Computer Science 2026-01-07 Yihong Guo , Junjie Luo , Guodong Gao , Ritu Agarwal , Anqi Liu

Conversational recommender systems proactively query users with relevant "key terms" and leverage the feedback to elicit users' preferences for personalized recommendations. Conversational contextual bandits, a prevalent approach in this…

Machine Learning · Computer Science 2025-05-28 Maoli Liu , Zhuohua Li , Xiangxiang Dai , John C. S. Lui

Computationally efficient contextual bandits are often based on estimating a predictive model of rewards given contexts and arms using past data. However, when the reward model is not well-specified, the bandit algorithm may incur…

Machine Learning · Computer Science 2021-06-14 Sanath Kumar Krishnamurthy , Vitor Hadad , Susan Athey

The contextual bandit framework is widely used to solve sequential optimization problems where the reward of each decision depends on auxiliary context variables. In settings such as medicine, business, and engineering, the decision maker…

Machine Learning · Statistics 2025-03-17 Kevin Li , Eric Laber

Mobile Context-Aware Recommender Systems can be naturally modelled as an exploration/exploitation trade-off (exr/exp) problem, where the system has to choose between maximizing its expected rewards dealing with its current knowledge…

Information Retrieval · Computer Science 2014-08-12 Djallel Bouneffouf

Exposure bias is a well-known issue in recommender systems where items and suppliers are not equally represented in the recommendation results. This bias becomes particularly problematic over time as a few items are repeatedly…

Information Retrieval · Computer Science 2024-08-09 Masoud Mansoury , Bamshad Mobasher , Herke van Hoof

In offline reinforcement learning-based recommender systems (RLRS), learning effective state representations is crucial for capturing user preferences that directly impact long-term rewards. However, raw state representations often contain…

Information Retrieval · Computer Science 2025-02-05 Siyu Wang , Xiaocong Chen , Lina Yao

The contextual bandit literature has traditionally focused on algorithms that address the exploration-exploitation tradeoff. In particular, greedy algorithms that exploit current estimates without any exploration may be sub-optimal in…

Machine Learning · Statistics 2020-04-21 Hamsa Bastani , Mohsen Bayati , Khashayar Khosravi

Reinforcement learning considers the problem of finding policies that maximize an expected cumulative reward in a Markov decision process with unknown transition probabilities. In this paper we consider the problem of finding optimal…

Machine Learning · Computer Science 2020-10-19 Santiago Paternain , Juan Andres Bazerque , Alejandro Ribeiro

We study contextual bandits with ancillary constraints on resources, which are common in real-world applications such as choosing ads or dynamic pricing of items. We design the first algorithm for solving these problems that handles…

Machine Learning · Computer Science 2015-08-03 Ashwinkumar Badanidiyuru , John Langford , Aleksandrs Slivkins