SAFER: Probing Safety in Reward Models with Sparse Autoencoder

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Shi, Wei, Xie, Ziyuan, Li, Sihang, Wang, Xiang
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866908799363710976
author Shi, Wei
Xie, Ziyuan
Li, Sihang
Wang, Xiang
author_facet Shi, Wei
Xie, Ziyuan
Li, Sihang
Wang, Xiang
contents Reinforcement learning from human feedback (RLHF) is a key paradigm for aligning large language models (LLMs) with human values, yet the reward models at its core remain largely opaque. In this work, we present Sparse Autoencoder For Enhanced Reward model (\textbf{SAFER}), a novel framework for interpreting and improving reward models through mechanistic analysis. Leveraging Sparse Autoencoders (SAEs), we uncover human-interpretable features in reward model activations, enabling insight into safety-relevant decision-making. We apply SAFER to safety-oriented preference datasets and quantify the salience of individual features by activation differences between chosen and rejected responses. Using these feature-level signals, we design targeted data poisoning and denoising strategies. Experiments show that SAFER can precisely degrade or enhance safety alignment with minimal data modification, without sacrificing general chat performance. Our approach contributes to interpreting, auditing and refining reward models in high-stakes LLM alignment tasks. Our codes are available at https://github.com/xzy-101/SAFER-code. \textit{This paper discusses topics related to reward model safety and may include discussions or examples that highlight potential risks or unsafe outcomes.}
format Preprint
id arxiv_https___arxiv_org_abs_2507_00665
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle SAFER: Probing Safety in Reward Models with Sparse Autoencoder
Shi, Wei
Xie, Ziyuan
Li, Sihang
Wang, Xiang
Computation and Language
Artificial Intelligence
Reinforcement learning from human feedback (RLHF) is a key paradigm for aligning large language models (LLMs) with human values, yet the reward models at its core remain largely opaque. In this work, we present Sparse Autoencoder For Enhanced Reward model (\textbf{SAFER}), a novel framework for interpreting and improving reward models through mechanistic analysis. Leveraging Sparse Autoencoders (SAEs), we uncover human-interpretable features in reward model activations, enabling insight into safety-relevant decision-making. We apply SAFER to safety-oriented preference datasets and quantify the salience of individual features by activation differences between chosen and rejected responses. Using these feature-level signals, we design targeted data poisoning and denoising strategies. Experiments show that SAFER can precisely degrade or enhance safety alignment with minimal data modification, without sacrificing general chat performance. Our approach contributes to interpreting, auditing and refining reward models in high-stakes LLM alignment tasks. Our codes are available at https://github.com/xzy-101/SAFER-code. \textit{This paper discusses topics related to reward model safety and may include discussions or examples that highlight potential risks or unsafe outcomes.}
title SAFER: Probing Safety in Reward Models with Sparse Autoencoder
topic Computation and Language
Artificial Intelligence
url https://arxiv.org/abs/2507.00665