Skip to content

Evidence Classification Standard

Giving uncertainty an honest name

Evidence classes are the vocabulary that keeps a possibility from becoming a fact by accident. This standard helps human readers understand how much weight to place on a statement and helps AI readers preserve the difference between verified knowledge, inference, hypothesis, and unknown.

Continue to the Confidence and Uncertainty Model to see how those classes become decisions about reliance.

Evidence Classes

  • E0 Unverified: assertion or observation without validated provenance.
  • E1 Corroborated: supported by more than one independent source or control.
  • E2 Authoritative: issued by a competent and authenticated authority.
  • E3 Reproducible: independently repeatable through documented method.
  • E4 Canonical: approved, signed, versioned, and registered within Stygia.

Quality Dimensions

Evidence shall be assessed for authenticity, relevance, independence, completeness, recency, reproducibility, bias, and chain of custody.

Rules

Evidence class does not equal truth. Authoritative evidence may be wrong. Repeated evidence may share a common source. CONAN shall preserve source relationships and identify material conflicts.

Claims used in consequential decisions shall link to evidence records, confidence, uncertainty, and known limitations.

Normative clauses

  • KNOW-R022: An evidence record shall assign one primary class and may assign separate quality dimensions, limitations, and confidence. No class shall be treated as a guarantee of truth.
  • KNOW-R023: E0 Unverified shall be used when provenance, authenticity, or material context has not been validated. E0 material may guide investigation but shall not alone support a consequential action.
  • KNOW-R024: E1 Corroborated shall identify the sources treated as independent and the basis for independence. Shared origin, copied reporting, or common unverified inputs shall not be counted as independent corroboration.
  • KNOW-R025: E2 Authoritative shall identify the issuing authority, authentication basis, scope, jurisdiction, and expiry or revocation conditions. Authority of issuance shall not establish the truth of every proposition in the record.
  • KNOW-R026: E3 Reproducible shall identify the method, inputs, environment assumptions, expected result, observed result, and independent reproduction record. Reproduction shall not cure an invalid premise or create authority.
  • KNOW-R027: E4 Canonical shall require approved status, valid registration, version identity, integrity evidence, and applicable publication controls. A canonical record remains subject to correction or supersession under its governing authority.
  • KNOW-R028: Classification changes shall append the prior class, new class, evidence considered, reason, reviewer, and effective time. Silent reclassification is prohibited.
  • KNOW-R029: Material conflicts, missing custody, altered digests, licensing uncertainty, stale evidence, and unavailable sources shall be recorded as limitations and shall block or bound dependent conclusions where warranted.
  • KNOW-R030: Consequential decisions shall link each material proposition to its evidence class, confidence, uncertainty, applicability, and unresolved dissent. A summary shall not sever those links.
  • KNOW-R041: Classification SHALL record the claim, consequence, evidence considered, evidence excluded, assessor, effective time, and reassessment trigger.
  • KNOW-R042: A class change SHALL identify whether the evidence changed, the claim changed, the consequence changed, or the applicability changed.
  • KNOW-R043: Evidence shall be minimised for purpose while preserving enough provenance, dissent, and limitation to support independent challenge.
  • KNOW-R044: Classification SHALL NOT create authority, consent, identity, permission, or access to protected material.

Classification procedure

The classifier shall first establish the claim being assessed, then record provenance and custody, assess quality dimensions, assign the class, and record confidence and limitations. The assessment shall identify evidence not considered where that exclusion could change the result. Reassessment shall be triggered by contradiction, expiry, revocation, material transformation, new corroboration, or a change in consequence.

Operating model and interpretation cases

Classification begins with the claim and consequence, then records provenance, custody, quality dimensions, class, confidence, limitations, applicability, and dissent. Reviewers distinguish copied repetition from independent corroboration and distinguish authority of issuance from truth of content. Reassessment follows contradiction, expiry, revocation, transformation, new corroboration, or changed consequence.

  • Conforming: Claim, class, quality, provenance, confidence, limitations, applicability, and dissent are linked.
  • Prohibited: A high class is treated as certainty or permission.
  • Boundary: Unknown or unavailable evidence supports only a bounded investigative claim.
  • Failure: Altered custody or conflicting sources reduce or block dependent conclusions.
  • Loophole: Copies of one source are counted as independent evidence.
  • Misuse: Classification exposes protected source contents or private identity.
  • Care-control: Evidence handling supports safety while preserving minimisation and agency.

Boundary conditions

Evidence classification governs epistemic handling only. It does not grant permission, create a person or agent, amend a constitutional rule, establish consent, or authorise access to private material. Such matters require the separate authority and decision records specified by the governing corpus.