On-Policy Self-Training paper: self-generated training data causes diversity collapse

idanbeck · x · 2026-10-27

The On-Policy Self-Training paper explores data-free self-improvement in LLMs, but flags a key catch: diversity collapse from self-generated training data. In a medical QA test, models tuned on raw frontier-API synthetic data ranked below the untrained base model — showing why diversity control is critical when training on synthetic data.

Related event: Google's OPST: LLM self-improvement without external data(3 posts)→

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