# Scalable Oversight and Weak-to-Strong Generalization

> Burns et al. (OpenAI Superalignment, "Weak-to-Strong Generalization", 2023) proposed a proxy for the superalignment problem: fine-tune a strong model using labels produced by a weaker model. If the strong model generalizes correctly from imperfect weak supervision, current human-scale alignment methods may extend to superhuman systems. Scalable oversight and W2SG are complementary. Scalable oversight (debate, recursive reward modeling, task decomposition) increases the overseer's effective capability so it can keep up with the model under oversight. W2SG ensures the strong model generalizes correctly from whatever imperfect supervision the overseer provides. Debate Helps W2SG (arXiv:2501.13124, January 2025) combines them.

**Type:** Learn
**Languages:** Python (stdlib, W2SG gap simulator)
**Prerequisites:** Phase 18 · 01 (instruction-following), Phase 18 · 10 (AI Control), Phase 09 (RL foundations)
**Time:** ~60 minutes

## Learning Objectives

- Define scalable oversight and weak-to-strong generalization and explain how they are complementary.
- Describe the Burns et al. 2023 experimental setup: fine-tune GPT-4 using labels from GPT-2.
- Explain the performance gap recovered (PGR) metric and what it measures.
- State the three major scalable-oversight mechanisms (debate, recursive reward modeling, task decomposition) and one strength of each.

## The Problem

Every alignment technique so far in Phase 18 assumes the overseer can evaluate the model's behaviour. When the model is superhuman, the overseer is the weak link. The superalignment question: can a weaker supervisor reliably produce a stronger, aligned model?

Burns et al. reduce this to an operationalized empirical setup: supervise strong with weak, measure how much of the strong model's capability survives the weak supervision. This is not a solution to superalignment — it is a proxy that lets us measure progress.

## The Concept

### W2SG: the Burns et al. setup

- Weak model: GPT-2 class.
- Strong model: GPT-4 class.
- Target: strong GPT-4 ceiling on the task.

Procedure:
1. Get weak model's zero-shot predictions on a task.
2. Fine-tune the strong model on weak-labeled data.
3. Measure the strong fine-tuned model's accuracy.

Baselines: weak model's own accuracy, strong model's supervised ceiling on gold labels.

Gap metric: Performance Gap Recovered (PGR) = (fine-tuned - weak) / (ceiling - weak). PGR of 1.0 means weak supervision fully closes the gap; PGR of 0 means weak supervision did not help.

### Burns et al. empirical findings

Across NLP, chess-puzzle, and reward-modeling tasks, PGR was consistently positive: the strong model generalized beyond the weak supervisor's mistakes. Task-specific PGR varied from ~20% to ~80%. The strong model "understands" the intended task from imperfect labels, filling in with its pre-trained priors.

Limitations Burns et al. note:
- The weak-to-strong gap here is capability, not alignment. The weak model is aligned; a truly superhuman model might be aligned by a human but with a much larger capability gap.
- The strong model's generalization may be more about task priors than about recovering ground-truth intent.
- Eliciting the strong model's latent knowledge is the real problem; PGR measures a specific operationalization.

### Scalable oversight: three mechanisms

- **Debate (Irving et al. 2018).** Two instances of U argue opposite sides; the weak judge decides. The assumption: finding a convincing true answer is easier than finding a convincing false answer. Recent 2024-2025 work (Khan et al., Michael et al.) shows debate sometimes helps and sometimes does not, and whether it helps depends on task structure.
- **Recursive Reward Modeling (Leike et al. 2018).** U helps the human train the reward model for U+1. The overseer's effective capability grows with the model's.
- **Task Decomposition (Christiano, Shlegeris, Amodei 2018).** Decompose a hard task into sub-tasks the human can check, recursively. Assumes decomposability.

Each mechanism assumes something about the structure of the task or the alignment of the intermediate components.

### Why scalable oversight and W2SG are complementary

Scalable oversight increases the overseer's effective signal quality.
W2SG closes the gap from whatever imperfect signal the overseer can provide.

Lang et al. — Debate Helps Weak-to-Strong Generalization (arXiv:2501.13124) combines them: a debate protocol provides better weak labels, and the strong model is trained on those labels. Reported PGR gains on NLP tasks.

### The organizational drama

OpenAI's Superalignment team dissolved in May 2024 after Jan Leike's departure to Anthropic. The agenda (scalable oversight, W2SG, automated alignment research) continued at Anthropic and at academic labs — MATS (Lesson 28), Redwood (Lesson 10), Apollo (Lesson 8), METR (Lesson 28). The organizational structure changed; the research questions did not.

### Where this fits in Phase 18

Lessons 6-10 describe the threat and the defensive paradigm under the assumption U is untrustworthy. Lesson 11 is the offensive paradigm: make the overseer strong enough to verify U's alignment. Lessons 12-16 then turn to the practical tooling of adversarial evaluation.

```figure
scalable-oversight
```

## Use It

`code/main.py` simulates a W2SG fine-tune on a synthetic task. Weak labeler has 70% accuracy with structured errors; strong model has 95% ceiling on gold labels. You fine-tune the strong model on weak labels, measure PGR, and compare to strong-on-gold and weak-alone.

## Ship It

This lesson produces `outputs/skill-w2sg-pgr.md`. Given an oversight setup description, it identifies the weak supervisor, the strong model, the supervision quality, and computes (or requests) PGR. It flags whether the claim is "weak can supervise strong" or "weak + oversight mechanism can supervise strong."

## Exercises

1. Run `code/main.py`. Report PGR for weak_accuracy = 0.60, 0.70, 0.80. Explain the shape of the PGR curve.

2. Modify the weak labeler to have structured error (e.g., always wrong on a specific input class). Does PGR increase, decrease, or stay the same? Explain.

3. Read Burns et al. 2023 Section 4.3 (NLP tasks). Reproduce the "confidence auxiliary loss" intuition: when the strong model is more confident than the weak labels, who wins?

4. Design a scalable-oversight protocol that combines debate and task decomposition for a software-engineering task. Name one failure mode of each component and explain how the combination addresses or fails to address each.

5. Articulate what would falsify the "weak-to-strong generalization is a viable path to superalignment" claim. Be specific about the empirical signature you would need to see.

## Key Terms

| Term | What people say | What it actually means |
|------|-----------------|------------------------|
| Scalable oversight | "making the overseer stronger" | Mechanisms that increase an overseer's ability to evaluate a more-capable model |
| W2SG | "weak supervises strong" | Fine-tuning a strong model on weak labels and measuring the capability recovered |
| PGR | "performance gap recovered" | (fine-tuned - weak) / (ceiling - weak); 1.0 = fully closed, 0 = no help |
| Debate | "two U instances argue" | Scalable oversight mechanism where a weak judge picks between two U defenders |
| RRM | "recursive reward modeling" | U helps train the reward model for U+1; overseer capability tracks U |
| Task decomposition | "sub-tasks the human checks" | Break a hard task into sub-tasks the human can verify, recursively |
| Superalignment | "aligning superhuman AI" | The research agenda concerned with aligning models the human cannot directly evaluate |

## Further Reading

- [Burns et al. — Weak-to-Strong Generalization (OpenAI 2023)](https://openai.com/index/weak-to-strong-generalization/) — the W2SG paper
- [Irving, Christiano, Amodei — AI safety via debate (arXiv:1805.00899)](https://arxiv.org/abs/1805.00899) — the debate mechanism
- [Leike et al. — Scalable agent alignment via reward modeling (arXiv:1811.07871)](https://arxiv.org/abs/1811.07871) — recursive reward modeling
- [Khan et al. — Debating with More Persuasive LLMs Leads to More Truthful Answers (arXiv:2402.06782)](https://arxiv.org/abs/2402.06782) — 2024 empirical study of debate with stronger debaters
- [Lang et al. — Debate Helps Weak-to-Strong Generalization (arXiv:2501.13124)](https://arxiv.org/abs/2501.13124) — 2025 combination of debate + W2SG
