arXiv Computation and Language

Bringing Value Models Back: Generative Critics for Value Modeling in LLM Reinforcement Learning

arXiv AI
Oct 2

Your Language Model is Its Own Critic: Reinforcement Learning with Value Estimation from Actor's Internal States

The paper introduces POISE, a reinforcement learning algorithm that uses a model’s internal states as a value estimator to reduce variance in reinforcement learning with verifiable rewards (RLVR). By employing a lightweight probe that reads internal signals during the forward pass, POISE predicts baselines online and uses a cross‑rollout construction to keep gradients unbiased. Experiments on Qwen3‑4B and OLMo3‑7B‑Instruct‑DPO across six domains show POISE outperforms existing RLVR baselines, offering more stable training and a value model that generalizes across tasks and scales with the policy.

By Yunho Choi, Jongwon Lim, Woojin Ahn, Minjae Oh, Jeonghoon Shim, Yohan Jo
arXiv Machine Learning
Jul 21

Implicit Actor Critic Coupling via a Supervised Learning Framework for RLVR

arXiv:2509. 02522v3 Announce Type: replace-cross Abstract: Recent advances in Reinforcement Learning with Verifiable Rewards (RLVR) have empowered large language models (LLMs) to tackle challenging reasoning tasks such as mathematics and programming, however existing RLVR methods often suffer from sparse reward signals and unstable policy gradient updates inherent to RL-based approaches.

By Jiaming Li, Longze Chen, Ze Gong, Yukun Chen, Lu Wang, Wanwei He, Run Luo, Min Yang
arXiv Machine Learning
1d ago

FOCUS: Active Critic Learning for Long-Horizon Language Model Agents

FOCUS is a reinforcement learning method designed to improve long‑horizon language‑model agents by using selective branching to train a critic network more accurately. The rollout controller actively samples continuations from states that are expected to reduce the critic’s estimation error, and the refined value estimates are used to score segments between consecutive states with a TD(λ) advantage. Experiments on legal reasoning, deep search, and code localization tasks show that FOCUS outperforms baselines such as GRPO and VinePPO, achieving significant accuracy gains on benchmarks like BrowseComp‑Plus and DeonticBench.

By Zhengping Jiang, William Jurayj, Liaoyaqi Wang, Chunsheng Zuo, Anqi Liu, Benjamin Van Durme