# Requirements — Paper A v4.0 (Big-4 reframe)

Milestone: Paper A v4.0 IEEE Access submission with Big-4-only primary scope and full-dataset secondary robustness.

## REQ-001: Big-4-only primary scope (foundation)

**What**: All primary statistical analysis (KDE+dip, BD/McCrary, Beta mixture, 2D-GMM K=2/K=3, pixel-identity FAR, held-out 70/30 z-test, classifier sensitivity) is rerun on the 437-CPA Big-4 subset (Firm A + KPMG + PwC + EY, n_signatures ≥ 10).

**Acceptance**:
- Script 20 rerun on Big-4 subset, dip-test p < 0.05 on cos_mean and dh_mean
- Script 21 (held-out validation) rerun on Big-4 subset
- Script 24 (calibration vs held-out z-test, classifier sensitivity) rerun on Big-4 subset
- Script 19 (pixel-identity / FAR) rerun on Big-4 subset
- All rerun outputs land under `reports/v4_big4/`
- New operational threshold cos > 0.975 AND dh ≤ 3.76 (or refined K=2 posterior) documented with bootstrap 95% CI

## REQ-002: Full-dataset robustness as secondary section

**What**: §IV-K (new) reports the full-dataset (686 CPA) version of the same analyses as a robustness check, demonstrating the pipeline runs at multiple scopes and explaining why the published v3.x 0.945 threshold drifted (mid/small-firm tail heterogeneity).

**Acceptance**:
- §IV-K table comparing Big-4-only vs full-dataset crossings, with mid/small-firm contribution analysis
- Explicit explanation of why Big-4 is the methodologically privileged primary scope

## REQ-003: Methodology rewrite (§III-G / I / J / L)

**What**: Sections III-G (unit hierarchy / scope), III-I (threshold estimators), III-J (accountant-level GMM), III-L (per-document classifier rule) rewritten to reflect dip-test confirmed bimodality and the new K=2-derived classifier rule.

**Acceptance**:
- §III-G justifies Big-4 as the methodological unit (sample size, homogeneity, dip-test evidence)
- §III-I anchored on bootstrap-stable bimodal evidence rather than three-method convergence on unimodal data
- §III-J reports K=2 as primary (interpretable: replicated vs hand-leaning) with K=3 BIC slightly preferred (-1112 vs -1108) as secondary
- §III-L derives operational rule from Big-4 K=2 components and bootstrap CI

## REQ-004: Results tables IV-XVIII regenerated

**What**: All results tables in §IV (currently Tables IV through XVIII at v3.20.0) regenerated on the Big-4 subset with consistent formatting and footnote citation to source script.

**Acceptance**:
- Each table cites the script + DB query that generated it
- Big-4 numbers replace full-dataset numbers as primary; full-dataset relegated to §IV-K
- Figures 1-4 regenerated; Fig 4 (yearly per-firm) likely reusable as-is

## REQ-005: Firm A reframed as templated case study

**What**: Throughout the manuscript, Firm A's role pivots from "calibration anchor (with minority hand-signers)" to "case study of the templated end of Big-4 (0% in K=3 hand-sign-leaning cluster, 82.5% in replicated cluster)". PwC's higher hand-sign tradition (24/102 = 23.5% in C1) noted as a Big-4 internal contrast.

**Acceptance**:
- Discussion (§V) explicitly states Firm A is the most digitally-replicated of Big-4
- Cross-tab table (firm × cluster) included in either §IV or §V
- Conclusion's contributions list updated accordingly

## REQ-006: AI peer review (≥3 rounds)

**What**: At least three cross-AI peer-review rounds on the v4.0 manuscript using codex (GPT-5.x), Gemini 3.x Pro, and Opus 4.7 max effort. Per `[[feedback-ai-review-provenance]]` memory: every reviewer-flagged empirical claim must be provenance-verified against fresh sqlite/grep against the named script.

**Acceptance**:
- Round 1 verdict obtained from each of the three reviewers
- All Major-class findings either RESOLVED in revision or explicitly disclaimed
- Final round produces ≥1 Accept / Minor verdict from at least 2 of 3 reviewers

## REQ-007: Partner Jimmy second review on v4.0

**What**: Jimmy (who proposed Big-4-only direction) reviews the v4.0 manuscript end-to-end before submission.

**Acceptance**:
- v4.0 DOCX shipped to ~/Downloads
- Jimmy's response captured in repo (paper/partner_jimmy_v4_review.md)
- Any must-fix items resolved in v4.0.x

## REQ-008: iThenticate + eCF + submission

**What**: iThenticate similarity check below 20%, IEEE eCF copyright form completed, manuscript uploaded via IEEE Access submission portal with cover letter.

**Acceptance**:
- iThenticate report saved under `paper/ithenticate_v4.pdf`
- eCF confirmation captured
- Submission portal confirmation number recorded in PROJECT.md "Validated" section

## Cross-cutting constraints

- **Reproducibility**: every script accepts a `--scope big4|full` flag (or new scripts under `signature_analysis/v4_*` if a flag refactor is too invasive)
- **Provenance**: every numeric claim in the paper traces to (script_id, DB query, output file) — see `[[feedback-provenance-fabrication]]`
- **No data re-ingest**: existing `/Volumes/NV2/PDF-Processing/signature-analysis/signature_analysis.db` is the frozen snapshot
- **Branch isolation**: all v4.0 work on `paper-a-v4-big4`; do NOT merge back to `yolo-signature-pipeline` until v4.0 is partner-approved