Writing study: Mitigating Reward Hacking in RLHF via Bayesian Non-negative Reward Modeling
← ICML 2026 oral writing corpus
Zhibin Duan, Guowei Rong, Zhuo Li, Bo Chen, Mingyuan Zhou, Dandan Guo · Official ICML 2026 oral record
Figure, table and section ledger
Editorial contribution type: Training, objectives & optimization (primary).
Layout extraction, not a required paper template. Counts are distinct caption labels; a multi-panel figure counts once. Section spans are estimated from heading positions, including floats and whitespace. Method and limitations.
- Canonical PDF
- 22 physical pages
- Before references / appendix
- ≈ 9.04 page-equivalents
- Main figures / tables
- 6 / 5
- Attached appendix figures / tables
- 4 / 6
- Attached appendix span
- ≈ 8.96 page-equivalents
Source-bound correction: Join wrapped printed heading text using adjacent source lines; original heading start coordinates are unchanged.
Section-by-section lengths and source pages
The title/abstract/front matter precede the first numbered heading. A span ends at the next detected top-level heading, not at the last sentence; end-page whitespace is included. References and statements are listed separately. These are not measurements of text-only or artwork area.
| Top-level heading | Starts on PDF page | Estimated span | Share of entire PDF |
|---|---|---|---|
| 1. Introduction | 1 | ≈ 1.02 pp. | 4.64% |
| 2. Related Work | 2 | ≈ 0.51 pp. | 2.32% |
| 3. Preliminaries | 3 | ≈ 0.68 pp. | 3.09% |
| 4. The Bayesian Non-negative Reward Model | 3 | ≈ 1.86 pp. | 8.45% |
| 5. Experiment | 5 | ≈ 3.13 pp. | 14.23% |
| 6. Conclusion | 8 | ≈ 0.85 pp. | 3.86% |
| Acknowledgements | 9 | ≈ 0.11 pp. | 0.5% |
| Impact Statement | 9 | ≈ 0.24 pp. | 1.09% |
| References | 10 | ≈ 4 pp. | 18.18% |
| A. Method Analysis | 14 | ≈ 3.7 pp. | 16.82% |
| B. Length and Formatting Debiasing and Interpretability | 17 | ≈ 0.91 pp. | 4.14% |
| C. Bayesian Non-negative RM Training Details | 18 | ≈ 1.13 pp. | 5.14% |
| D. Best-of-N (BoN) Test | 19 | ≈ 3.22 pp. | 14.64% |
All detected figure and table locations
Main text
Argument and organization
- 1 Introduction; 2 Related work; 3 Preliminaries
Connects noisy preference labels and surface-form bias to the reward-hacking problem.
- 4 Bayesian Non-negative Reward Modeling
Introduces the generative reward model, approximate inference and an explanatory factor interpretation.
- 5 Experiments; 6 Conclusion; Limitations
Separates reward quality, policy outcomes and debiasing analyses before narrowing the tested setting.
Problem, claim and contribution
The motivation distinguishes annotation noise from length/style bias, allowing the proposed local factors and global weights to answer different parts of the problem.
Abstract and Section 1, p.1 · Main paper
Argument and section order
Generative assumptions precede the variational implementation and a separate intuition subsection, so the model definition is not conflated with the inference network.
Sections 4.2-4.4, pp.4-5 · Main paper
Figures, captions and visual explanation
The main schematic contrasts scalar reward with factorized reward, while the later diagnostic page separates reward-length distributions, binned means and a dual-axis latent-factor display.
Figures 1-2, p.3; Figures 5-6, p.9 · Main paper
Tables, comparisons and evidence
Policy benchmarks show both positive and adverse deltas; a separate human/judge comparison states win, tie and loss from the proposed model’s perspective rather than substituting reward-model accuracy for policy evaluation.
Table 3, p.7; Tables 4-5, p.8 · Main paper
Appendix and reproducibility
The appendix places complexity and model analysis separately from training and label-noise construction, making the reproducibility protocol distinguishable from mathematical interpretation.
Appendix A, p.14; Appendix C, p.18 · Main paper
Clarity and writing conventions
The limitations name sensitivity to the KL coefficient and the lack of demonstrated multi-turn, tool-use and long-horizon transfer; the impact discussion separately addresses optimizing harmful rewards.
Limitations and Impact Statement, p.9 · Main paper
What to reuse—and what not to infer
Transferable lesson: Distinguish model assumptions, approximate implementation, reward diagnostics and downstream policy evidence in both the prose and the display sequence.
Boundary: Reduced length correlation and selected factor examples are not independent proof of causal debiasing or universal interpretability; the broader interactive settings remain untested.
Apply this lesson using the argument and evidence worksheet.
Inspection record and sources
- Checked
- 2026-10-07
- Reading status
- Writing-focused manuscript scan + selected visuals inspected
- Main text
- Writing-oriented scan of the main argument through physical p.9, with focused physical-page text inspection on 1, 3, 5, 7, 8, 9. Framing, section progression, mechanism/proof explanation, displays, comparison conditions and conclusions were inspected. This is not exhaustive technical reading, proof verification or reproduction.
- Appendix / supplement
- Appendix organization and main-text pointers were checked; focused text inspection of physical pages 14, 18. Remaining appendix proofs and details were not exhaustively read. No separately linked supplement inspected.
- Visually inspected PDF pages
- 3, 9
This is a writing-focused scan of the manuscript and the stated supplementary scope: framing, organization, visual explanation, evidence presentation and wording. It is not a line-by-line proof audit, reproduction of results or exhaustive scientific review.