Slide-split audit report
Date: 2026-08-27
Outcome
FAIL — the Q2 HiESD corpus was not slide-disjoint from the four M1 held-out reference fields. The three excluded_slides values committed in the Q2 configurations were malformed 32-character identifiers rather than the exact hyphenated HiESD UUIDs recorded in manifests/m1_source_fields.csv. Both corpus construction and verification compared those strings literally, so the intended exclusions did not match any source slide and the gate passed incorrectly.
The exact held-out manifest SHA-256 is 18377920a2dcca040e05ce875e4c7ecfe7a3f09d512539bf69d2eb681a26d0af. Its three unique slide UUIDs are:
0d55cc29-bb23-4d0d-8b79-93f70be520b80dddc3e2-b189-43fb-81c1-d0cac38f3cbd1a203f16-4d3c-440a-a6f1-82619763a54c
Leakage count
The 128-image no-overlay/caption-neutral corpus contains 40 fields from held-out slides:
| Category | Leaked fields | Category total |
|---|---|---|
| Normal | 8 | 32 |
| H. pylori-gastritis | 12 | 32 |
| Intestinal metaplasia | 12 | 32 |
| Mixed | 8 | 32 |
| Total | 40 | 128 |
The invalid normal-specialist corpus contains eight held-out-slide fields among its 32 normal fields. None of the 40 training crops has the exact M1 reference coordinate, but slide-level separation—not coordinate inequality—was the preregistered boundary, so this does not rescue the experiments.
Scientific impact
- Q0 and Q1 infrastructure findings remain valid because Q0 is untrained and Q1 used a separate GAGL smoke corpus.
- Q2 v1, no-overlay, prompt-ablation, and caption-neutral artifact-integrity and execution records remain reproducible, but every held-out similarity/generalisation result and checkpoint-selection conclusion is invalid.
- Caption-neutral epoch 3 is no longer an accepted tissue scaffold. It is an exploratory artifact only until a corrected slide-disjoint experiment independently reproduces the result.
- Q3 operational findings about exact-canvas assembly, seams, denoising, shutdown, and failure handling remain engineering evidence. Their biological/category conclusions cannot qualify any checkpoint for submission because the upstream LoRA used the invalid corpus.
- Normal-specialist run
20260826T184640Z-lora-traincompleted with valid hashes but is scientifically rejected. No checkpoint or validation image may be selected from it.
Root cause and correction
The builder and verifier accepted arbitrary exclusion strings and had no cryptographic binding to the held-out manifest. The correction:
- replaces every Q2 and specialist exclusion with the exact canonical UUID;
- requires canonical hyphenated UUIDs in corpus construction and verification;
- requires the held-out manifest as an input, verifies its SHA-256 through the preregistered config, and requires the configured exclusion set to equal the manifest's unique slide set;
- proves the old corpus now fails with
Held-out slide entered corpus; - keeps all GPU compute stopped until a new IOFlood-built corpus contains zero records from the three held-out UUIDs and passes full mechanical and visual review.
The corrected corpus receives new metadata/provenance hashes and a new protocol version. Historical artifacts and reports are preserved rather than overwritten.
Corrected rebuild v2 gate
The first genuinely slide-disjoint rebuild completed on IOFlood and passed independent remote and local mechanical verification:
- 128 images, exactly 32 per category;
- 13 source slides;
- zero records from the three M1 held-out slide UUIDs;
- metadata SHA-256
ab54ffb3b4f4e22a81595319e31481f23b43950ef4054ee76711b3c5c2a95e29; - provenance SHA-256
8fc600045163585961cb4557fb832c89e788c9a0e8572bf43b74758866b9426e; - local verification SHA-256
4bd619e53f7c120931b236b8458af3a645b2846302a359389db3c1c0d270802f.
It nevertheless fails the engineering visual input gate. Three normal crops from slide 6c6bcc80-c875-471e-87e9-1aef6725d80e (0009, 0011, and 0012) are dominated by blank space and torn/pale tissue rather than a continuous gastric field. Their fractions of pixels below mean RGB intensity 230 are 0.275, 0.254, and 0.321. No specialist run may use this corpus.
The preregistered v3 correction applies one category-independent real-input rule before selection: at least 50% of crop pixels must have mean RGB intensity below 230. It evaluates up to twelve non-overlapping candidates per slide/category but retains at most four, preserving the prior slide-diversity cap while allowing inadequate fields to be replaced. The rule is applied uniformly to all real candidate categories and recorded in provenance. It does not use synthetic outputs, Sydney labels, or generator artifacts. The v3 rebuild must again pass the split, hash, dimension, full contact-sheet, and full-resolution visual gates before GPU work resumes.
Corrected rebuild v3 result
The v3 rebuild passes the bounded engineering input gate:
- 128 exact 1024×1024 RGB PNGs, 32 per category, from 13 non-held-out slides;
- zero provenance records from the three M1 held-out slide UUIDs;
- at most four selected fields per slide/category;
- minimum stained-pixel fractions of 0.537 normal, 0.509 H. pylori-gastritis, 0.506 intestinal metaplasia, and 0.578 mixed;
- metadata SHA-256
ab54ffb3b4f4e22a81595319e31481f23b43950ef4054ee76711b3c5c2a95e29; - provenance SHA-256
59c826ee7693826cef2eef55f1f7c931b88a270026e8bfee33435e20ddd2398e; - independent local-verification SHA-256
2b2ac5ddc09643159c8853253f084760e15acb45ad2e122d39cb9cd5fd98effe; - deterministic 32-field review-sheet SHA-256
0208eb502f83565bcc70c062061c57a6a7d4fc1bc4906a3759ce8864cf941867.
The review sheet and the lowest-coverage field in every category were inspected at full resolution. All contain interpretable gastric tissue rather than the blank/torn-field failure seen in v2. This is an engineering input-adequacy decision only; it does not validate the source category annotations or replace pathologist review.
The first orchestration wrapper returned exit code 1 after image construction because it supplied the caption-neutral prompt override while verifying the base-prompt corpus. Re-running the verifier with the corpus's actual pinned prompt set passes. The failed wrapper status is retained as procedural evidence; the corpus was not rebuilt or altered after verification.
The hash-preserving caption-neutral view changes only the 64 positive captions and has metadata SHA-256 0fa3b61a6b76e311b52af163f9ea621efbd00a868769046d7c3954f6d1d11ac9. Its corrected specialist views are:
- normal: metadata
024754db101c6371b6e67f4f1247df921ab63b6ba618afcb2aa5c07578a2bf9a, provenance4d66a9d56dd9c9beef75fedebd3f69c7b04b8c4411a90f546048f585efab2831, 32 fields from nine slides; - intestinal metaplasia: metadata
5ba91f805d795680790a87c2fa3f94afabc17aa95968a3cf6729f7188533fc5d, provenance7449e3d94e0ac90ddcaf3ed5aeb83a688bd441e095c50c889ce4fdd10d022bdb, 32 fields from eight slides.
Both specialist views independently pass the strengthened held-out, hash, scale, dimension, and prompt gate. They restore eligibility for only the preregistered normal-versus-intestinal-metaplasia specialist pair; they do not restore any conclusion from the invalid historical Q2/Q3 runs.