engineering.conformity.z_score

Three distinct suites: educational examples on the calculator page, this legacy regression count (13/13 golden + boundary), and the CVP verification suite below. They are not the same number. Property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the CVP Manifest . SKIP (0/0) means that suite has no published vectors.

This calculator CURRENT · Public schema 1.0.1 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

CVP verification suite

Protocol checks from the Evidence Manifest. Distinct from the legacy regression suite above. Verification revision 2026-09-25.o2-o3. Calculation version 1.0.1. CVP 1.0.0-proposed. 4/4 golden · 6/6 CVP boundary · 6/6 invalid · 1/1 property · 1/1 metamorphic · 8/8 O3 · 3/3 cross-interface · 6/6 CVP contract. digest e0f1dac3e62d. O2: proficiency-testing z-score vs a separate-module division identity (≤2 ULP). Not zeta, not En, and not an ILAC G8 specification decision. ≤2 ULP vs O3 applies only to the published tabulated z-score vectors (pass, the |z|=2 boundary, warning, fail, an alias, a negative result, one awkward pair, and another |z|=2 pair). It is not a whole-domain guarantee and does not cover zeta, En, or an ILAC G8 specification decision.

• Golden (oracle-backed) 4 / 4
• CVP boundary 6 / 6
• Invalid input 6 / 6
• Property 1 / 1
• Metamorphic 1 / 1
• O3 high-precision 8 / 8
• Cross-interface 3 / 3
• CVP contract 6 / 6
• Interfaces PASS · UI (SSR) / REST / MCP
• Interface claim ui-ssr is query-result HTML, not a live browser session. Error-path engine·REST·MCP 1/1 (status, code, calculation_version). SSR compared on URL-canonical requested calculations; empty query is idle (not an error) and JSON-typed object/array inputs are REST/MCP-only.
• Verified scope Proficiency-testing z-score from ylab, xref, and a scheme σ_pt, + O3 mpmath tabulated z-score.
• Assurance Engineering
• Deferred Not zeta (laboratory u), not En (expanded U), and not an ILAC G8 specification decision.

• release artifacts aligned PASS
• schema output required declared PASS
• schema valid input executes PASS
• engine success output validates schema PASS
• schema rejects incomplete input PASS
• rest success payload validates schema PASS

Fingerprint sha256:3588cd334cfc05d7589f6f985c2f248e307616d5e6e7604e43de2f3bc374e04e

Input schema sha256:891fbf40a7ed8b147f092e7fcf6df696938c211d814d44423039ec5aef1f1936 · Output schema sha256:6534410340fd21a04b80659cdedefa4ea48ed1f7221a9f6bd3d5c72cdf318f1a · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Tool

z-score

Engine

z-score

Engine build

2026-09-24

Evidence core

2026-09-24T21:19:14.853Z

Rendered

2026-10-23T01:27:11.175Z

Last reviewed

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Assumptions

• ISO 13528 z-score with scheme SDPA σ_pt
• |z| ≤ 2 is pass; 2 < |z| < 3 is warning; |z| ≥ 3 is fail
• Not zeta (lab u), not En (expanded U), not TUR, and not an ILAC G8 spec decision

Limitations

• σ_pt is the scheme SDPA — this page does not compute lab u or U = k·u
• Not the zeta-score (that uses √(ulab²+uref²))
• Not the normalized error En (that uses already-expanded U)
• Not TUR and not an ILAC G8 specification decision on y
• |z| ≤ 2 is pass; 2 < |z| < 3 is warning; |z| ≥ 3 is fail