pith:O6M274A4
Rethinking Layer Relevance in Large Language Models Beyond Cosine Similarity
Cosine similarity can be arbitrarily low for a layer that is still essential to an LLM's performance.
arxiv:2605.14075 v1 · 2026-05-13 · cs.LG · cs.CL
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Claims
Our theoretical analysis shows that a layer can exhibit an arbitrarily low cosine similarity score while still being crucial to the model's performance. Empirical evidence confirms that the correlation between cosine similarity and actual performance degradation is often weak or moderate.
That removing a single layer and measuring accuracy drop on held-out tasks gives a faithful picture of that layer's contribution inside the intact model, without major compensatory effects from remaining layers.
Cosine similarity poorly predicts performance degradation from layer removal in LLMs, making direct accuracy-drop ablation a more reliable relevance metric.
References
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| First computed | 2026-05-17T23:39:12.373908Z |
|---|---|
| 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/O6M274A44LUGGWHN2K3BP56J2B \
| jq -c '.canonical_record' \
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Canonical record JSON
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