engineering.measurement.duplicate_sd

Three distinct suites: educational examples on the calculator page, this legacy regression count (8/8 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 · 4/4 CVP boundary · 4/4 invalid · 1/1 property · 1/1 metamorphic · 8/8 O3 · 2/2 cross-interface · 6/6 CVP contract. digest 24091842c569. O2: repeatability from duplicates s_r = sqrt(Σ d² / (2m)) vs a separate-module identity (≤2 ULP). Not r = 2.8 s. ≤2 ULP vs O3 applies only to the published tabulated duplicate-sd vectors. Not r = 2.8 s.

• Golden (oracle-backed) 4 / 4
• CVP boundary 4 / 4
• Invalid input 4 / 4
• Property 1 / 1
• Metamorphic 1 / 1
• O3 high-precision 8 / 8
• Cross-interface 2 / 2
• 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 ISO 5725 s_r = sqrt(Σ d² / (2m)) from m≥2 differences, + O3 mpmath tabulated duplicate sd.
• Assurance Engineering
• Deferred Not r = 2.8 s and not Gauge R&R.

• 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:dc6bb345487268f21fb74f6ec1b72f4beaca5fe6b6d6c2231260d1ae7fc04762

Input schema sha256:8c3e695177b7646874c27e0351185c153ffb865e99a5eab3d153db147c112ac7 · Output schema sha256:eca2e8d7374c35a286cb1100f2b1e987acbbad987497935ee137d3c45284081d · 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

duplicate-sd

Engine

duplicate-sd

Engine build

2026-09-24

Evidence core

2026-09-24T23:02:14.035Z

Rendered

2026-10-22T08:54:34.791Z

Last reviewed

—

Assumptions

• ISO 5725 duplicate-difference repeatability: s_r = √(Σ d_i² / (2m)) from m≥2 pairs. m=1 is rejected.
• d_i may be negative or zero. Both zero is valid (s_r = 0).
• Not Type A from a sample of observations, not r = 2.8·s, and not AIAG GRR EV = R̄/d2.

Limitations

• Takes duplicate differences — not a sample of observations
• m=1 is rejected so this cannot wrap |d|/√2
• Does not report r = 2.8·s_r
• Not AIAG GRR EV = R̄/d2