AI edits another AI's weights to lift Qwen3.5-0.8B from 7.9% to 48.1% on MATH-500 — mostly a bug fix

geoffwolfe · x · 2026-11-03

A viral post claims MIT researchers had GPT-6 Astra improve Qwen3.5-0.8B without training by editing just 0.016% of its weights, raising MATH-500 from 7.9% to 48.1%. Astra, given the weights and a 50-run test budget, traced the model's self-repetition to an internal signal written by two layers and subtracted it out.

But the reposter notes it mostly fixed a bug: Astra found and removed a repetition loop in Qwen's weights, and did almost nothing on a model without that loop. Still, an AI debugging another AI by reading its weights is wild.

Related event: MIT's Weight-Space Programming: LLM Directly Edits Weights, Boosting Math Scores 6x(42 posts)→

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