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Related papers: Inference-Time Reward Hacking in Large Language Mo…

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Exploration is essential in reinforcement learning as an agent relies on trial and error to learn an optimal policy. However, when rewards are sparse, naive exploration strategies, like noise injection, are often insufficient. Intrinsic…

Machine Learning · Computer Science 2026-01-30 Minjae Cho , Huy Trong Tran

Reward models (RMs) are crucial for the training and inference-time scaling up of large language models (LLMs). However, existing reward models primarily focus on human preferences, neglecting verifiable correctness signals which have shown…

Computation and Language · Computer Science 2025-02-27 Hao Peng , Yunjia Qi , Xiaozhi Wang , Zijun Yao , Bin Xu , Lei Hou , Juanzi Li

Aligning generative models with human preference via RLHF typically suffers from overoptimization, where an imperfectly learned reward model can misguide the generative model to output undesired responses. We investigate this problem in a…

Machine Learning · Computer Science 2024-12-05 Zhihan Liu , Miao Lu , Shenao Zhang , Boyi Liu , Hongyi Guo , Yingxiang Yang , Jose Blanchet , Zhaoran Wang

Learning about many things can provide numerous benefits to a reinforcement learning system. For example, learning many auxiliary value functions, in addition to optimizing the environmental reward, appears to improve both exploration and…

Machine Learning · Computer Science 2020-08-25 Cam Linke , Nadia M. Ady , Martha White , Thomas Degris , Adam White

Reward Models (RMs) are crucial for online alignment of language models (LMs) with human preferences. However, RM-based preference-tuning is vulnerable to reward hacking, whereby LM policies learn undesirable behaviors from flawed RMs. By…

Computation and Language · Computer Science 2026-03-05 Daniel Fein , Max Lamparth , Violet Xiang , Mykel J. Kochenderfer , Nick Haber

Large Language Models (LLMs) excel at problem solving by generating chain of thoughts in natural language, but such verbal thinking is computationally costly and prone to overthinking. A recent work instead proposes a latent thinking…

Computation and Language · Computer Science 2026-02-25 Hanwen Du , Yuxin Dong , Xia Ning

To convey desired behavior to a Reinforcement Learning (RL) agent, a designer must choose a reward function for the environment, arguably the most important knob designers have in interacting with RL agents. Although many reward functions…

Machine Learning · Computer Science 2022-06-01 Henry Sowerby , Zhiyuan Zhou , Michael L. Littman

The remarkable progress in text-to-video diffusion models enables the generation of photorealistic videos, although the content of these generated videos often includes unnatural movement or deformation, reverse playback, and motionless…

Computer Vision and Pattern Recognition · Computer Science 2025-10-08 Yuta Oshima , Masahiro Suzuki , Yutaka Matsuo , Hiroki Furuta

Reinforcement Learning from Verifiable Rewards (RLVR) has recently shown that large language models (LLMs) can develop their own reasoning without direct supervision. However, applications in the medical domain, specifically for question…

Machine Learning · Computer Science 2025-09-22 Mirza Farhan Bin Tarek , Rahmatollah Beheshti

Reward models trained on human preference data have demonstrated strong effectiveness in aligning Large Language Models (LLMs) with human intent under the framework of Reinforcement Learning from Human Feedback (RLHF). However, RLHF remains…

Leveraging inference-time search in large language models has proven effective in further enhancing a trained model's capability to solve complex mathematical and reasoning problems. However, this approach significantly increases…

Machine Learning · Computer Science 2025-10-29 Tianwei Ni , Allen Nie , Sapana Chaudhary , Yao Liu , Huzefa Rangwala , Rasool Fakoor

Reward hacking is a form of misalignment in which models overoptimize proxy rewards without genuinely solving the underlying task. Precisely measuring reward hacking occurrence remains challenging because true task rewards are often…

Machine Learning · Computer Science 2026-04-21 Muhammad Khalifa , Zohaib Khan , Omer Tafveez , Hao Peng , Lu Wang

Reinforcement learning from human feedback usually models preferences using a reward function that does not distinguish between people. We argue that this is unlikely to be a good design choice in contexts with high potential for…

Large Language Models (LLMs) demonstrate strong capabilities in general coding tasks but encounter two key challenges when optimizing code: (i) the complexity of writing optimized code (such as performant CUDA kernels and competition-level…

Machine Learning · Computer Science 2026-01-12 Jiefu Ou , Sapana Chaudhary , Kaj Bostrom , Nathaniel Weir , Shuai Zhang , Huzefa Rangwala , George Karypis

While direct policy optimization methods exist, pioneering LLMs are fine-tuned with reinforcement learning from human feedback (RLHF) to generate better responses under the supervision of a reward model learned from preference data. One…

Machine Learning · Computer Science 2025-06-10 Chuheng Zhang , Wei Shen , Li Zhao , Xuyun Zhang , Xiaolong Xu , Wanchun Dou , Jiang Bian

Reinforcement Learning from Human Feedback (RLHF) has enabled significant advancements within language modeling for powerful, instruction-following models. However, the alignment of these models remains a pressing challenge as the policy…

Machine Learning · Computer Science 2024-06-21 Ahmed M. Ahmed , Rafael Rafailov , Stepan Sharkov , Xuechen Li , Sanmi Koyejo

Inference scaling helps LLMs solve complex reasoning problems through extended runtime computation. On top of long chain-of-thought (long-CoT) models, purely inference-time techniques such as best-of-N (BoN) sampling, majority voting, or…

Existing approaches to LLM personalization focus on constructing better personalized models or inputs, while treating inference as a single-shot process. In this work, we study Test-Time Personalization (TTP) along an unexplored axis:…

Machine Learning · Computer Science 2026-05-13 Linhai Zhang , Yulan He

Reward modeling has emerged as a promising approach for the scalable alignment of language models. However, contemporary reward models (RMs) often lack robustness, awarding high rewards to low-quality, out-of-distribution (OOD) samples.…

Reward models are used throughout the post-training of language models to capture nuanced signals from preference data and provide a training target for optimization across instruction following, reasoning, safety, and more domains. The…

Computation and Language · Computer Science 2026-04-24 Saumya Malik , Valentina Pyatkin , Sander Land , Jacob Morrison , Noah A. Smith , Hannaneh Hajishirzi , Nathan Lambert