Verification
8/8 calculation tests · Production surface contract 4/4
- Golden tests 0 / 0
- Boundary tests 5 / 5
- Property tests 3 / 3
- Production surface contract 4 / 4
}
- Engine tested Yes
- Source checked Yes
- Artifact integrity PASS
- Production attestation Embedded snapshot: STALE · Last attested schema matched 1.0.0 snapshot / local build · Semantic contract ✓ · Last attestation PASS · current evidence changed · re-attestation required · Public/cache ✓ · Origin ✓ · Live production status PASS (0 stale; 164 CURRENT) @ 2026-09-16T06:44:24.909Z
- Semantic contract PASS
- Evidence attested at 2026-09-16T06:44:24.203Z
- Last production check 2026-09-16T06:44:24.203Z
- Public / cache PASS
- Origin PASS
- Supplemental domain review Not performed
- Named expert review Not performed
- release artifacts aligned PASS
- schema valid input executes PASS
- engine success output validates schema PASS
- schema rejects incomplete input PASS
Fingerprint sha256:9ce4e6f368b473483310c22bdcf9392af1368150be6a13bececbd7f2dcfa96d7
Input schema sha256:9df2c14e2a0bd90df92a6b43f0ace6bbdf7a0291d6514b2febc035bdc4024748 · Output schema sha256:c655b77686e92e8138f442f7f6f36a4ead7cdd219d3a6d2b5f9f6e69859b2c5b · 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.
Engine identity and declared limitations.
- Tool
- pooled-sd
- Engine
- pooled-sd
- Engine build
- 2026-09-16
- Evidence core
- 2026-09-16T21:07:40.795Z
- Rendered
- 2026-09-16T22:38:08.855Z
- Last reviewed
- —
Assumptions
- Pooled standard deviation: s_p = √(Σ ν_i s_i² / Σ ν_i) from k≥2 stated groups. ν_i > 0 and finite.
- s_i ≥ 0. Both zero is valid (s_p = 0).
- Not Type A from one sample, not Welch–Satterthwaite ν_eff, and not ISO 21748 u of a mean.
Limitations
- Takes stated s_i and ν_i — not a single sample of observations
- k=1 is rejected so this cannot wrap Type A / identity s
- Does not compute Welch–Satterthwaite ν_eff
- Does not compute ISO 21748 u of a mean
Sources
Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.
- JCGM 100:2008 — Evaluation of measurement data (GUM) — 4.2.4 Type A evaluation from several series
Supports: Independent series of observations of the same measurand may be pooled: s_p² is the ν-weighted mean of the sample variances.
- ISO 5725-2 — Repeatability and reproducibility of standard measurement methods — Pooled repeatability standard deviation
Supports: s_p is the usual pooled-within estimate from several groups. This page takes stated s_i and ν_i rather than a collaborative-study table.
Published checks
Golden, boundary, and property cases included in this evidence build.
| ID | Kind | Status | Detail |
|---|
boundary-pool | boundary | pass | Expected s_p=5 · nu=2 · k=2 · Actual s_p=5 · nu=2 · k=2 |
boundary-pool-equal | boundary | pass | Expected s_p=5 · Actual s_p=5 · nu=11 · k=2 |
boundary-pool-n | boundary | pass | Expected s_p=5 · Actual s_p=5 · nu=2 · k=2 |
boundary-pool-one | boundary | pass | Expected VALUE_OUT_OF_RANGE · Actual VALUE_OUT_OF_RANGE |
boundary-pool-missing | boundary | pass | Expected MISSING_REQUIRED_INPUT · Actual MISSING_REQUIRED_INPUT |
property-pool | property | pass | 5 |
property-pool-equal | property | pass | 5 |
property-pool-alias | property | pass | 5 |
