Writing study: Half-order Fine-Tuning for Diffusion Model: A Recursive Likelihood Ratio Optimizer
← ICLR 2026 oral writing corpus
Tao Ren, Zishi Zhang, Jinyang Jiang, Zehao Li, Shentao Qin, Yi Zheng, Guanghao Li, Qianyou Sun, Yan Li, Jiafeng Liang, Xinping Li, Yijie Peng · Official ICLR 2026 oral record
Figure, table and section ledger
Editorial contribution type: Learning & optimization algorithms (primary) · Inference, algorithms & systems efficiency.
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
- 27 physical pages
- Before references / appendix
- ≈ 9.2 page-equivalents
- Main figures / tables
- 6 / 5
- Attached appendix figures / tables
- 5 / 5
- Attached appendix span
- ≈ 12.89 page-equivalents
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 | 2 | ≈ 1.36 pp. | 5.04% |
| 2 RELATED WORK | 3 | ≈ 0.2 pp. | 0.74% |
| 3 UNBIASED MINIMAL VARIANCE GRADIENT ESTIMATOR FOR DIFFUSION | 3 | ≈ 1.14 pp. | 4.22% |
| 4 SOLVING THE VARIANCE MINIMIZATION PROBLEM: RECURSIVE | 4 | ≈ 1.57 pp. | 5.81% |
| 5 EXPERIMENTS | 6 | ≈ 2.3 pp. | 8.52% |
| 6 THEORETICAL PROPERTIES OF GRADIENT ESTIMATORS: BIAS, VARIANCE, | 8 | ≈ 1.08 pp. | 4% |
| 7 CONCLUSION | 9 | ≈ 0.34 pp. | 1.26% |
| ACKNOWLEDGMENTS | 10 | ≈ 0.09 pp. | 0.33% |
| REFERENCES | 10 | ≈ 4.91 pp. | 18.19% |
| A EXTENDED RELATED WORKS | 15 | ≈ 0.49 pp. | 1.81% |
| B EXPERIMENTS SETTINGS | 15 | ≈ 2.11 pp. | 7.81% |
| C HYPEPARAMETERS | 17 | ≈ 0.41 pp. | 1.52% |
| D QUALITATIVE RESULTS OF TEXT2IMAGE | 18 | ≈ 1 pp. | 3.7% |
| E QUALITATIVE RESULTS OF TEXT2VIDEO | 19 | ≈ 1 pp. | 3.7% |
| F DETAILS FOR DIFFUSIVE CHAIN-OF-THOUGHT EXPERIMENT | 20 | ≈ 1.3 pp. | 4.81% |
| G MEMORY PROFILE, TIME COMPLEXITY, AND DIFFERENT DIFFUSION | 21 | ≈ 0.89 pp. | 3.3% |
| H ABLATIONS ON THE SUB-CHAIN LENGTH h | 22 | ≈ 0.35 pp. | 1.3% |
| I MORE RESULTS ON VBENCH | 22 | ≈ 0.87 pp. | 3.22% |
| J PROOFS | 23 | ≈ 4.49 pp. | 16.63% |
All detected figure and table locations
Main text
Argument and organization
- Estimator design space
Explains the memory–bias–variance tradeoff before introducing the hybrid estimator.
- RLR and diffusion experiments
Pairs local-gradient design with image/video reward experiments and a restricted prompt-decomposition demonstration.
- Theory and implementation appendix
Separates regularity assumptions, estimator proofs, memory/time accounting and sampler settings.
Problem, claim and contribution
The opening compares full differentiation, truncated differentiation and policy gradients as competing resource tradeoffs; this gives the hybrid design an intelligible motivation before its equations.
Sections 1 and 3, pages 1–4 · Main paper
Argument and section order
The paper first defines the recursive generation process, then narrows a large estimator design space to a local half-order subchain plus zeroth-order and direct terms.
Sections 3–4, pages 3–5 · Main paper
Figures, captions and visual explanation
Figure 4 overlays a symbolic denoising chain and image examples, using separate arrows for forward computation, perturbation and differentiation. The legend makes the three gradient-estimation regions readable.
Figure 4, page 3 · Main paper
Tables, comparisons and evidence
The appendix distinguishes per-step speed from time to reach a common aesthetic score and reports host RAM separately from GPU memory. Those are more informative comparisons than an isolated memory-saving percentage.
Appendix G, Tables 6–7, page 21 · Main paper
Appendix and reproducibility
A contents page routes readers to hyperparameters, prompt templates, qualitative samples, solver checks, subchain ablations and proofs. The same-score timing and longer-subchain costs belong near the main efficiency claim.
Appendix contents page 14; Appendices C and G–J · Main paper
Clarity and writing conventions
Some theoretical statements need narrower wording: the perturbation proof concerns its explicitly randomized process, and the variance appendix's claim that the direct term has zero variance is not a general consequence of having no injected parameter noise.
Appendix J.3–J.4, pages 24–26 · Main paper
What to reuse—and what not to infer
Transferable lesson: Make an optimizer's tradeoff concrete with one computation-graph legend and a table separating peak device memory, host memory, step time and time to a common target.
Boundary: Do not repeat an unconditional minimum-variance or unbiased-for-the-unperturbed-model claim. The proof uses a perturbed recursion, regularity assumptions and a restricted estimator construction; automatic reward gains are not a human preference study.
Apply this lesson using the argument and evidence worksheet.
Inspection record and sources
- Checked
- 2026-09-19
- Reading status
- Full text + selected visuals inspected
- Main text
- Pages 1–9, Sections 1–7; reference list on pages 10–13 checked for source organization
- Appendix / supplement
- Pages 14–27, contents and Appendices A–J including all proof and resource tables
- Visually inspected PDF pages
- 3, 21
- ICLR 2026 final proceedings · 27 pages