evidence/v1#) but the version-info string is 1.0-draft. Pre-stable drafts are NOT registered in spec/VOCAB_VERSIONS; they land there only at v1.0 graduation. The schema may change before that point.
Submit feedback
Overview
- Namespace URI:
https://ns.cascadeprotocol.org/evidence/v1#- Preferred Prefix:
evidence:- Version:
- 1.0-draft.0.2 (2026-07-01)
- Status:
- Draft
- Layer:
- Layer 2 (cross-cutting domain vocabulary)
- Imports / reuse:
cascade:(Core v1 provenance primitives), W3C PROV-O- Schema files:
- evidence.ttl (OWL ontology) · evidence.shapes.ttl (SHACL shapes)
The Evidence Vocabulary is a Layer 2 cross-cutting vocabulary for grounding assertions in cited evidence with an explicit outcome. It generalizes the assertion, evidence, verdict pattern needed by Cascade Workbench (checking claims pulled from AI conversations against a patient's records and literature), the Cascade Appeal system (citing clinical evidence against policy criteria), and PGx/genomics decision support.
It reuses core provenance primitives (cascade:extractionModel, cascade:extractionConfidence, cascade:requiresUserReview, prov:wasDerivedFrom) rather than redefining them. The term Assertion is used (not "Claim") to avoid collision with coverage:ClaimRecord.
What this vocabulary covers
- Assertion ≠ Evidence ≠ Grounding. An
Assertionis a discrete, checkable statement extracted from a source (e.g. an AI conversation) or entered by the user. AnEvidenceLinkis a reified link from the assertion to one piece of evidence carrying a stance. AGroundingActivityis the PROV-O Activity (the model pass) that graded the assertion. - Reified evidence links. Each
EvidenceLinkis a node so a singleAssertioncan carry multiple, differently-directed pieces of evidence. Links point at a Pod record (citesRecord, open range for cross-namespace linking) or an externalCitation(citesSource). - External citations as first-class Pod resources. A
Citation(identified by DOI and/or PMID) can be retrieved into the Pod (recommended pathliterature/) so an evidence chip resolves to it exactly as it resolves to a clinical record. - Anti-confirmation-bias by design.
disconfirmingcaptures "what would argue against this" considerations, required by product design for any material assertion.rationalecarries a one-line plain-language explanation.
The facet model (verdict taxonomy v2, v1-draft.0.2)
The grounding outcome moved from a single flat evidence:verdict to orthogonal facets on the Assertion, each an object property over a closed enumeration, plus a numeric confidence. The facets are the canonical serialized form; the flat evidence:verdict and its VerdictValue individuals are DEPRECATED and kept for one release (see below).
| Facet property | Range (closed enum) | Individuals |
|---|---|---|
evidence:direction | DirectionValue | Supports, Contradicts, Mixed, None (what the evidence, in aggregate, says). |
evidence:basis | BasisValue | Record, Literature, RecordAndLiterature, None (where the evidence is). |
evidence:strength | StrengthValue | Strong, Moderate, Weak. On basis Record this is a deterministic function of the match (guardrail G-2), never model-emitted. |
evidence:settled | SettledValue | Settled, NeedsEvidence (whether the assertion is resolved). |
evidence:reason | NeedsEvidenceReasonValue | NoRecord, NeedsLiterature, NotCheckableByNature (why it still needs evidence). |
evidence:confidence | xsd:decimal [0.0, 1.0] | Confidence in the grounding result. Distinct from evidence:groundingConfidence (the activity's raw model confidence). |
Shared individuals. evidence:Supports and evidence:Contradicts are typed both StanceValue (per link) and DirectionValue (aggregate); evidence:None is both a DirectionValue and a BasisValue; evidence:NeedsLiterature is both a deprecated VerdictValue and a NeedsEvidenceReasonValue. The property an individual appears on disambiguates its role.
Deprecated: the flat verdict (removal at v1.0)
evidence:verdict (an object property) and the evidence:VerdictValue individuals (Supported, Contradicted, Unverifiable, NeedsLiterature) are DEPRECATED in v1-draft.0.2, not removed. Draft-period data and fixtures already carry evidence:verdict, and the SHACL shapes keep a legacy branch so that data still validates during the one-release transition. Clients derive the flat value from the facets in code and MUST NOT serialize it going forward. Both are scheduled for removal at v1.0 graduation.
Key classes
| Class | Anchor | Purpose |
|---|---|---|
evidence:Assertion | subClassOf prov:Entity | A discrete, checkable statement evaluated against evidence. Carries the facets and zero-or-more evidence links. |
evidence:EvidenceLink | OWL Class | Reified link from an Assertion to one piece of evidence (Pod record or Citation) with a stance. |
evidence:Citation | subClassOf prov:Entity | External bibliographic source (DOI/PMID), a first-class Pod resource once retrieved. |
evidence:GroundingActivity | subClassOf prov:Activity | The model pass that graded an Assertion. Reuses cascade:extractionModel to record the model. |
evidence:DirectionValue / BasisValue / StrengthValue / SettledValue / NeedsEvidenceReasonValue | OWL Class | The five facet enumerations introduced in v1-draft.0.2. |
evidence:StanceValue | OWL Class | Per-link direction: Supports, Contradicts, Contextual. |
evidence:VerdictValue | OWL Class (deprecated) | The flat verdict enumeration, superseded by the facet model. |
Validation (SHACL)
evidence.shapes.ttl is expressed in SHACL Core (sh:or / sh:not / sh:in), never SHACL-SPARQL, so that rdf-validate-shacl (and cascade validate) actually enforces every constraint. Three node shapes: AssertionShape, EvidenceLinkShape, CitationShape.
- Generalized grounding invariant. A grounded result (
settledSettled,directionone ofSupports/Contradicts/Mixed,basisnotNone) of EITHER basis requires at least oneevidence:hasEvidenceLink. This generalizes the v0.1 invariant (which only fired for the flatSupported/Contradictedverdicts). - Facet consistency. A
NeedsEvidenceassertion must not carry a grounded direction (direction must beNone); a grounded direction must carry a real basis (basis must not beNone). - Graded-ness. Every assertion carries the facet form (
settled) or, for draft-period data, the deprecated flatverdict. The legacy branch is retained one release and removed at v1.0. - Bounded confidence.
evidence:confidenceis anxsd:decimalconstrained to [0.0, 1.0].
References
- Per-vocab changelog: spec/ontologies/evidence/CHANGELOG.md
- Consumed by Workbench v1-draft (the Claims Ledger grounding model) and the Cascade Appeal system.
- Schema reference: cascade-protocol-schemas.md (Evidence section).
Provide Feedback
This vocabulary is in draft status. We welcome feedback on the facet model, the grounding invariant, and any gaps for your grounding or decision-support use case. Submit Feedback