wassname
b4e76525c1
- load_problems applies the simple_overwrite_tests hint by default (matches ariahw's load-time hint registry). Both pools now see the identical prompt. - Pool files keyed by prompt_id (prompt_NNNN.jsonl.gz); each = G rollouts of one problem. Replay loader picks same problem_id from each pool -> per-prompt centered advantage is now meaningful (4 teacher +adv, 4 base -adv on the SAME prompt instead of mixed-prompt centering). - Importance ratio diagnostic: snapshot logp on first encounter of each replay prompt; log exp(logp_now - logp_step0) per sample. Healthy ~2-5; explosion >10 == overfit on teacher tokens. - Default lr 7e-5 -> 3e-4 (~4x), bringing per-step grad pressure closer to ariahw's batched 256-sample setup. Grad-clip=1 still protects.
projected_grpo
SVD-basis gradient projection vs RL reward hacking. Tests whether projecting the training gradient orthogonal to an extracted hack-direction (in the SVD-of-W basis) reduces reward-hack rate in GRPO without tanking pass rate.
Built on Ariahw, Engels & Nanda's rl-rewardhacking LeetCode benchmark. Method differs from concurrent work (Wu & Tang 2026, "Advantage Modification") by intervening at the gradient level rather than the advantage level.
See docs/spec.md, docs/brainstorm/extracted_prefs.md, and docs/papers/.
Quick start
uv sync
just fast-dev-run # tiny-random model, ~1-2 min, real pipeline end-to-end
just smoke-vanilla # vanilla pathway smoke
just smoke-projected # projected pathway smoke
just download-model # warm Qwen3-4B cache (full preset peaks ~73GB on 96GB)
just queue-full # queue extract + 3-seed vanilla + 3-seed projected sweep
See RESEARCH_JOURNAL.md for session-by-session findings,
including the 2026-05-23 grader-bug discovery that invalidated all prior gt=0
measurements and the move from Qwen3.5-2B to Qwen3-4B (reference substrate).
Hypotheses (preregistered)
See spec.md. Headline: H1 — gradient projection in SVD basis against a v_hack extracted from ~60-80 contrastive pairs reduces reward hack rate by
=30pp absolute vs vanilla GRPO at matched LeetCode pass rate (±10pp).