Learning from the Right Rollouts: Data Attribution for PPO-based LLM Post-Training
- URL: http://arxiv.org/abs/2604.01597v1
- Date: Thu, 02 Apr 2026 04:09:31 GMT
- Title: Learning from the Right Rollouts: Data Attribution for PPO-based LLM Post-Training
- Abstract summary: We propose textbfInfluence-Guided PPO (I-PPO), a novel framework that integrates data attribution into the RL post-training loop.<n>I-PPO consistently outperforms SFT and PPO baselines.
- Score: 25.736034135647554
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: Traditional RL algorithms like Proximal Policy Optimization (PPO) typically train on the entire rollout buffer, operating under the assumption that all generated episodes provide a beneficial optimization signal. However, these episodes frequently contain noisy or unfaithful reasoning, which can degrade model performance and slow down training. In this paper, we propose \textbf{Influence-Guided PPO (I-PPO)}, a novel framework that integrates data attribution into the RL post-training loop. By calculating an influence score for each episode using a gradient-based approximation, I-PPO identifies and eliminates episodes that are anti-aligned with a validation gradient. Our experiments demonstrate that I-PPO consistently outperforms SFT and PPO baselines. We show that our filtering process acts as an intrinsic early stopping mechanism, accelerating training efficiency while effectively reducing unfaithful CoT reasoning.
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