pith:6CAYQMLC
Prefix Teach, Suffix Fade: Local Teachability Collapse in Strong-to-Weak On-Policy Distillation
In strong-to-weak on-policy distillation, truncating supervision at the onset of local teachability collapse outperforms full-trajectory training.
arxiv:2605.13643 v1 · 2026-05-13 · cs.CL
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Claims
supervision should concentrate on trajectory regions where the teacher's feedback remains discriminative, rather than uniformly covering the entire response. We operationalize this principle through a trajectory-specific release rule... Experimental results... indicate that this release rule consistently outperforms standard full-trajectory OPD across five in-domain benchmarks.
That the BIC-style downward change point on NLTK-sentence-aggregated teacher margins over the student's top-K set reliably identifies the onset of local teachability collapse without prematurely cutting useful supervision or retaining non-discriminative tokens.
Local teachability collapse in trajectory suffixes makes uniform dense supervision suboptimal in strong-to-weak OPD; truncating at BIC-style change points on teacher margin improves performance.
References
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| First computed | 2026-05-18T02:44:17.571911Z |
|---|---|
| Builder | pith-number-builder-2026-05-17-v1 |
| Signature | Pith Ed25519
(pith-v1-2026-05) · public key |
| Schema | pith-number/v1.0 |
Canonical hash
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curl -sH 'Accept: application/ld+json' https://pith.science/pith/6CAYQMLC2AWU7XRFPLFHJHAFOB \
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Canonical record JSON
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