# InfoTechCanon Evidence Basis Catalog
#
# How a quantity was obtained. Owned by ITC-GOV; imported by CapabilityConsumption
# (CAP-R10) and reusable on any measured or modelled value.
#
# Adapted from demand/EvidenceBasis.md (resource-control). Strength is a tier,
# not a total order: invoiced and measured are peers. The consumer's first
# implementation used a strict list rank and corrected it.
canon:
  id: itc-gov-evidence-basis
  name: InfoTechCanon Evidence Basis
  artifact_id: catalog/evidence-basis
  version: 0.1.0
  status: draft
  canon_version: 0.4.0
  owner: model/governance
  purpose: Closed scale for how a quantity was obtained, with a propagation rule
    and decision grades. Tiers, not a spurious total order.
  normative_document: models/governance/InfoTechCanonGovernanceModel.md
  provenance:
    demand: demand/EvidenceBasis.md
    consumer: resource-control
    consumer_docs:
      - docs/evidence-basis.md
      - tools/basis.py
bases:
  - id: invoiced
    tier: evidenced
    description: Taken from an authoritative financial record. This canon names
      the basis; it does not originate booked costs, tax, or currency semantics.
  - id: measured
    tier: evidenced
    description: Directly observed from the authoritative system.
  - id: quoted
    tier: evidenced
    description: Stated by a provider or counterparty in a citable source.
  - id: derived
    tier: null
    description: Computed from other values by a stated rule. Not a resolved
      tier — effective basis is the weakest input.
  - id: projected
    tier: projected
    description: Interpolated between, or extrapolated beyond, observations.
  - id: estimated
    tier: judgement
    description: Human judgement, neither observed nor computed.
  - id: assumed
    tier: judgement
    description: A modelling constant chosen by the author.
  - id: unknown
    tier: unknown
    description: No value exists. MUST NOT carry a quantity. MUST name the gap
      and its owner.
# Strongest to weakest. Members of one tier are peers: weakest() among only
# invoiced and measured MUST NOT imply a ranking. quoted is evidenced for
# decision grades but sits below that peer pair for propagation.
tiers:
  - id: observed
    rank: 0
    members: [invoiced, measured]
    evidenced: true
    note: peers. An invoice is authoritative for a payment; a measurement is
      authoritative for a quantity. Neither outranks the other.
  - id: quoted
    rank: 1
    members: [quoted]
    evidenced: true
    note: stated by a counterparty. Weaker than observed for propagation;
      still evidenced for decision grades.
  - id: projected
    rank: 2
    members: [projected]
    evidenced: false
  - id: judgement
    rank: 3
    members: [estimated, assumed]
    evidenced: false
    note: both yield decision grade indicative; they are not ranked against
      each other.
  - id: unknown
    rank: 4
    members: [unknown]
    evidenced: false
rules:
  - id: weakest-input-wins
    statement: A derived value is only as strong as its weakest input, compared
      by tier. Members of the same tier do not rank against each other.
  - id: unknown-is-not-zero
    statement: Basis unknown carries no quantity. Any other basis MUST carry a
      quantity. Zero means measured-and-none; unknown means not measured.
  - id: derived-names-inputs
    statement: A derived value MUST record derived_from. Only a derived value
      MAY record derived_from.
  - id: invoiced-not-originated
    statement: invoiced names a booked fact owned elsewhere. This catalog does
      not define ledger semantics.
  - id: tiers-not-total-order
    statement: Strength is a tier, not a total order. weakest([invoiced,
      measured]) MUST NOT imply that one outranks the other.
qualifiers:
  - id: proxy_for
    description: The value measures a different quantity than the one being
      reasoned about. It does not weaken the measurement; it weakens the
      inference.
  - id: observed_at
    description: When a measurement was taken. Age and sample size are not
      basis. A value may be measured and still be a single noisy sample.
decision_grades:
  - id: evidenced
    when: Every load-bearing value resolves to an evidenced tier
      (observed or quoted).
  - id: projected
    when: The weakest resolved tier is projected.
  - id: indicative
    when: The weakest resolved tier is judgement (estimated or assumed).
  - id: insufficient
    when: At least one load-bearing value is unknown.
note: >
  EvidenceBasis is how a quantity was obtained. It is not the
  intended/declared/applied/observed/assessed state qualifier (OQ-3). Those
  name which world a claim is about; this names how a number in that world
  was produced.