ppo-clipping-mechanism
IN premise — entries/2026/06/21/wiki-Reinforcement_learning_from_human_feedback-chunk-5.md
Created 2026-06-21T09:50:10+00:00
PPO's clipping mechanism constrains the ratio of new-to-old policy probabilities, preventing destructively large policy updates — this is what makes it 'proximal'.
Summary
When the agent learns a new way of acting, this mechanism acts like a speed limiter, capping how far the new behavior can deviate from what it was doing before. Without that guardrail, a single training step could wipe out everything the agent had already learned, so the limit is what keeps the learning process stable and recoverable.