← dashboard · all hypotheses · run ledger

V6 — Preprocessing-fit leakage is corpus-specific and cannot be assumed small

PARTIAL registered EVALUATION axis A4 (preprocessing-fit scope), A3 pinned at `speaker_disjoint` 1 run(s) on disk

Everything in this block was recorded in version control before any run. It is rendered above the result on purpose: a prediction a reader meets after the number it predicted is not a prediction.

The claim

The inflation from fitting the scaler/normaliser before splitting varies by an order of magnitude across corpora, so "we scaled before splitting but it's a small effect" is not defensible on an unmeasured corpus.

The published claim it audits

Feature scaling induced data leakage quantification in machine learning-based voice pathology detection, Applied Soft Computing (S1568494626007970): 1,000 repetitions per configuration; effect −0.14 to +0.14 pp on SVD but −8.3 to +7.8 pp on VOICED. Leakage can degrade as well as inflate. This is a published measurement on two corpora; the audited proposition is its generalisation to the corpora this program actually uses, and to embedding features rather than handcrafted ones.

Pre-registered falsifier

If the fit_on_all − fit_per_fold AUC difference has a 95% CI contained within ±0.01 AUC on all of SVD, Coswara, COUGHVID for both eGeMAPS and a frozen SSL representation, the "corpus-specific magnitude" claim is falsified for this pipeline family and preprocessing scope can be de-prioritised as an audit axis.

Predicted effect (recorded before the run)

Effect < 0.01 AUC on SVD (reproducing the published near-null) and > 0.03 AUC on at least one of Coswara/COUGHVID; sign not predicted (the published result shows both directions).

Power and scope

tier (as registered)EVALUATION
family size m / seeds nm = 6 (3 corpora × 2 representations) · n = 10 → 0.001953 ≤ 0.008333 ✓
datasetsSVD · Coswara · COUGHVID
costFree — re-fits a scaler on cached features.
min attainable paired p0.001953
Holm-tightest threshold 0.05/m0.008333
arithmetically satisfiable under R6✓
registry statusPARTIAL — SVD near-null reproduced on embeddings; falsifier NOT evaluable — see F5

Registry status is read from the ## Summary table of IDEA_TABLE.md, which the author maintains as a set. The per-block status cells are maintained one at a time and disagree with it; one source of truth, and this is it.

Measured result

EVALUATION n = 10 repeats against the pre-registered family (m = 6 (3 corpora × 2 representations) · n = 10 → 0.001953 ≤ 0.008333 ✓): min attainable paired p = 0.001953 ≤ Holm 0.05/m = 0.008333. Feasible. Feasibility is a property of the design, not of the result — it says what this run could have shown.

Scaler-fit-before-split leakage, measured on embeddings

EVALUATION PARTIAL -- near-null reproduced; falsifier NOT evaluable n = 10 × 5 folds SCOPE-LIMITED

0.0042
max |delta AUC| across the cells that ran
3 / 6
cells run / cells pre-registered
1,679
speakers
28,509 recordings

Artifact autoresearch_results/V6_preprocessing_leakage.json · written 2026-07-28 14:03 UTC · full run page → · written up as F5 in FINDINGS.md

Full detail from the primary artifact

Rendered from autoresearch_results/V6_preprocessing_leakage.json. Every other run for this hypothesis, including controls, has its own page linked above.

Pre-registered cells — including the ones that did not run

corpusbackbonerecordingsspeakersAUC, scaler fit on ALLAUC, scaler fit per folddelta (leak - honest)95% CI on deltastatus
svdwavlm28,5091,6790.73820.73820.00004[0.0000, 0.0001]RUN
svdegemaps667490.53150.5357-0.00418[-0.0063, -0.0022]RUN
coswarawavlm610720.49290.49060.00236[0.0004, 0.0048]RUN
coswaraegemapsnot yet measurednot yet measurednot yet measurednot yet measurednot yet measurednot yet measuredNOT RUN -- no cached embeddings
coughvidwavlmnot yet measurednot yet measurednot yet measurednot yet measurednot yet measurednot yet measuredNOT RUN -- no cached embeddings
coughvidegemapsnot yet measurednot yet measurednot yet measurednot yet measurednot yet measurednot yet measuredNOT RUN -- no cached embeddings

3 of 6 pre-registered cells ran. The unrun cells are the corpus-specificity arm — the part of this hypothesis that is actually novel. The near-null reproduced on SVD is a reproduction of the audited paper's point, not the new claim, so the falsifier is not evaluable and the finding is PARTIAL. Artifact self-report: all_within_pm_0.01 = True.