How the zigzag LoRA was trained: per-layer gradient signals with output forced to match the original model

Sauers_ · x · 2026-10-20

@Sauers details the zigzag training method: a rank-16 LoRA trained across various prompts/questions while forcing answers to match the original model (no token generation change), also minimizing KL from the base model. Training is per-layer, with separate gradient signals for each layer-token pair — maximizing probe readout on even layers and minimizing it on odd layers (or vice versa). The author floats follow-ups: a single signal per token, or zig-zagging the entire activation norm instead, which would be easy to learn without disrupting general processing if the cat vector is small in activation space.

Related event: Researcher Trains Qwen3's Internal Representations Into a Zigzag Pattern(9 posts)→

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