Coverage Completeness Audit¶
Completeness audit — instantiates Patchwise Global Certification
Maps the union of the patches against the declared domain to prove no in-scope region is left unwitnessed, and logs every gap it finds.
The Coverage Completeness Audit proves that the union of the patches actually equals the declared domain — that no in-scope region, case, or interface is left unwitnessed — and logs every gap it finds. It takes the cover and the witness records and maps them against the domain, hunting specifically for holes. It is not the list of patches, which the inventory owns; it is the proof that the list leaves nothing out. Where the inventory asserts the union is meant to span the whole, the audit is the step that tests that assertion and reports where it fails.
Example¶
A county health department wants to claim "every child under five in the county is up to date on measles vaccination." It cannot inspect "the county" as one object; it holds per-clinic and per-census-tract records — the patches. The Coverage Completeness Audit overlays the union of those records onto the county's map of under-five residents and looks for uncovered cells: a census tract with no reporting clinic, children who moved between tracts and fall in the seam, a shelter population attached to no clinic patch at all. Each uncovered region is logged as a gap. The audit's finding might read: "reported coverage is 94%, but three tracts and the shelter population — roughly 1,100 children — are represented by no patch whatsoever; the 94% was computed over a domain that silently excludes them." That gap, not the headline percentage, is the audit's product, and it is what keeps the eventual certificate from overclaiming.
How it works¶
- Take the domain and the cover. Start from the declared domain and the inventory's patch set; compute or estimate the union of the patches.
- Map union against domain. Lay the union over the domain and identify every uncovered region, case, or interface.
- Classify the gaps. Distinguish never-covered from stale from genuinely out-of-scope.
- Log to the register. Record each uncovered region as an entry in the exception register for adjudication.
Tuning parameters¶
- Resolution — how fine the coverage map's cells are; finer resolution finds smaller holes at higher cost.
- Gap tolerance — what fraction of the domain may be uncovered while a scoped claim is still permitted.
- Domain definition source — whose census, boundary, or requirement list defines "the whole," which shifts what even counts as a gap.
- Re-audit cadence — a one-time check versus periodic re-mapping as the domain drifts.
When it helps, and when it misleads¶
Its strength is that it catches the failure of a global claim made from a set of patches that does not actually cover the domain — the sampled-but-presented-as-complete error that no amount of local passing can reveal.
Its failure mode is undercoverage that is invisible because the domain itself is defined by the cover: if the denominator of "children under five" is built from clinic lists, the children in no clinic's list cannot appear as a gap.[n1] The classic misuse is computing coverage over the covered set and reporting it as coverage of the whole. The guarding discipline is to define the domain independently of the cover — from a source that does not inherit the cover's blind spots — so the holes have somewhere to show up.
How it implements the components¶
coverage_completeness_map— its core: the map of union against domain, and the located holes it exposes.obstruction_or_exception_register— it writes each uncovered region into the exception register as a coverage-gap entry, feeding the adjudication.
Does not implement local_cover_or_patch_set — enumerating and justifying the patches themselves is the job of Patch Cover Inventory, its nearest twin. The inventory lists the pieces; the audit proves they leave no gap.
Related¶
- Instantiates: Patchwise Global Certification — the audit supplies the completeness proof the certificate depends on.
- Consumes: Patch Cover Inventory supplies the cover whose union the audit tests against the domain.
- Sibling mechanisms: Patch Cover Inventory · Local Witness Checklist · Overlap Compatibility Test · Gluing or Recomposition Workflow · Obstruction Register Review · Global Certificate Template · Local-to-Global Dashboard
Editorial Notes¶
Form Classification¶
Form family: Assessment, Review & Assurance
Rationale: Coverage Completeness Audit operates as a bounded evaluation of existing evidence or work that produces a finding or disposition because it maps the union of the patches against the declared domain to prove no in-scope region is left unwitnessed, and logs every gap it finds.
Independent corroboration: The frozen evidence defines Coverage Completeness Audit as 'Maps the union of the patches against the declared domain to prove no in-scope region is left unwitnessed, and logs every gap it finds', so its operative form is Assessment, Review & Assurance.
Review outcome: Independent reviewer agreement; high confidence.
Origin Attribution¶
Primary origin: Accounting & Auditing
Origin pattern: Cross-disciplinary synthesis
Present-day reach: Multi-domain
Rationale: Audit practice cohered systematic reconciliation of declared scope against assembled evidence to identify every unwitnessed item or region.
Related originating lineages:
- Computer Science & Software Engineering — Test coverage and requirements traceability supply machine-checkable gap detection across specified domains.
- Mathematics — Set theory supplies the union-equals-domain criterion and formal notion of a cover with no holes.
- Statistics & Experimental Design — Survey-frame and sampling methodology supplies explicit undercoverage tests against a declared target population.
Review resolution: Reconciling declared scope against assembled evidence and logging every unwitnessed item is fundamentally an audit operation. Statistics, mathematics, and computer science each supply a formative completeness lineage; the generalized patch-union proof is synthetic and broadly usable but not literally universal.
Attribution caveat: The patch-union proof synthesizes audit completeness, survey undercoverage, test coverage, and mathematical cover reasoning.
Encyclopedia synthesis: The exact catalogued form synthesizes established practice rather than reproducing a single standard historical label.
Review outcome: Researched adjudication after independent review; medium confidence.
Sources consulted:
- GAO Government Auditing Standards: Sufficiency and completeness of audit evidence
- U.S. Census Bureau Statistical Quality Standards: Coverage and undercoverage
Notes¶
[n1] Undercoverage occurs when the frame used to sample or measure a population omits part of that population, so any estimate computed from it silently excludes the missing members. It is the coverage audit's central quarry — the gaps a cover cannot see because it defines the very denominator against which coverage is judged. ↩