Frozen LLM critics sharpen credit assignment for long-horizon agents

LVRL uses a pretrained model to redistribute sparse terminal rewards across individual actions without training a separate value network.

Big Tech
Kaijie Zhu · Weixiang Yan · Omar Attia · Abbas Kazerouni · Alexander Toshev · Andrew Szot

Apple

Research Digest··2 min read
Zhu et al.

6 model to estimate values for intermediate states after observing the completed trajectory.

Why this paper

From Apple · Part of Multi-Turn Credit Assignment, now 4 papers

In one line

A frozen LLM value critic, policy-aware via in-context conditioning, improves step-level credit assignment in agentic RL, beating GRPO and PPO.

What we could check

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  • ·No weights link found
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  • ✓Limitations stated by the authors (3 noted)
  • ✓Reports numbers on named benchmarks (4 benchmarks)

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Research Digest

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