1.5 KiB
Research Journal
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2026-05-23
Project init
Scaffolded repo per setup-repo skill. Cloned external/rl-rewardhacking (Ariahw's verl-based GRPO + LeetCode reward-hacking benchmark) and fetched the three key papers (docs/papers/):
- Ariahw, Engels, Nanda 2025 (LessWrong) — the benchmark and monitor-based interventions
- Wu & Tang 2026 (arXiv 2604.01476) — "When Reward Hacking Rebounds"; proposes Advantage Modification using shortcut concept direction. This is the closest prior work to ours and the H3 baseline arm.
- Ichihara et al. 2025 (arXiv 2509.22047) — MO-GRPO; multi-objective GRPO with per-reward variance normalization. Related framing of reward hacking as high-variance reward dominating advantage.
Extracted brainstorm prefs to docs/brainstorm/extracted_prefs.md. Biggest delta vs spec.md: the project pivoted mid-brainstorm from DPO+sycophancy to GRPO+reward-hacking, and the method evolved from bidirectional NLL+KL+PCGrad (paired-preference) to gradient-level projection (unpaired). Confidence ~60% the method works post-Rebound (was ~40% pre-Rebound; Rebound validates the core mechanism — concept-direction-based intervention — but at advantage rather than gradient level).
Next: smoke test both pathways on tiny-random Qwen, prototype the results table, then move to 96GB GPU for the H4 sanity run.