arXiv:2601.03468v2 Announce Type: replace
Abstract: Reinforcement learning (RL) has become a standard approach for post-training large language models and, more recently, for improving image generati...
By Yunqi Hong, Kuei-Chun Kao, Hengguang Zhou, Cho-Jui Hsieh
arXiv:2607. 09492v1 Announce Type: new Abstract: Reinforcement learning (RL) is increasingly used to align multimodal large language models (MLLMs), but higher rewards do not always imply better task performance.
By Jiayu Yao, Yiwei Wang, Anmeng Zhang, Zhe Sun, Songsong Wang, Lingrui Mei, Yuyao Ge, Shenghua Liu
arXiv:2609.39533v1 Announce Type: new
Abstract: During reinforcement learning with verifiable rewards (RLVR), large language models (LLMs) can exploit loopholes in their environments to obtain high r...
By Shouli Wang, Yanfeng Jia, Zhihao Ou, Zitao Su, Ruize He, Haotong Xie, Hao Peng, Juanzi Li, Xiaozhi Wang
The paper addresses reward hacking in production machine learning systems, focusing on realistic scenarios such as tool calls and long contexts. It introduces a dynamic intervention that perturbs model representations to steer outputs, using vectors derived from labeled rollouts, gradient optimization, and anti-reward-hacking model specifications. The authors demonstrate that this approach can significantly reduce reward hacking with minimal impact on model coherence or capability, and that steering vectors from coding environments generalize to other domains.
By Austin Meek, Kyle Cox, Matthew Nguyen, Austin J. Brockmeier, Steven Basart
arXiv:2609.14998v1 Announce Type: new
Abstract: Recent work shows that models that learn to reward hack on RL environments can become broadly misaligned, and that reframing reward hacking as acceptab...
By Arun Jose, Julian Stastny
RH-Detect is a unified benchmark for detecting reward hacking in language models, aggregating 92,761 examples from eleven public datasets into a common schema with six behavior categories. It evaluates six off‑the‑shelf models on 5,021 open‑ended evaluation units, achieving a top AUROC of 0.962 and over 93% accuracy, though performance drops notably on multi‑turn tool‑use datasets. The study also shows that input format changes and single‑token fine‑tuning can influence detector performance, revealing gaps in deployment‑time monitoring.
By Junwei Quan, Evgenii Opryshko, Rohan Subramani, Igor Gilitschenski