Grail Computer · research record
Dated experiment record. Statements describe this run, not current submission readiness. Historical H. pylori category names do not establish infection; copy screens are bounded tests. Claims that a source does not exist mean none was identified in that recorded search, not proof of absence. Licensing interpretations in the notes remain unconfirmed. Local access details have been omitted. Current limitations and remaining work.

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:

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

Root cause and correction

The builder and verifier accepted arbitrary exclusion strings and had no cryptographic binding to the held-out manifest. The correction:

  1. replaces every Q2 and specialist exclusion with the exact canonical UUID;
  2. requires canonical hyphenated UUIDs in corpus construction and verification;
  3. 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;
  4. proves the old corpus now fails with Held-out slide entered corpus;
  5. 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:

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:

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:

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.

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