{
  "id": "COMP-ONT-001",
  "slug": "ontology",
  "status": "Informative Comparison",
  "subject": "OCOM",
  "target": "Ontology",
  "targetShort": "ONT",
  "summary": "OCOM and ontologies both formalize meaning, but at different layers. An ontology (RDFS, OWL) defines classes, properties and logical axioms so machines can reason about what terms mean and infer new facts. OCOM defines a governed operating model, objects with identity, ownership, lifecycle, policy and evidence, for running an organization. An ontology answers 'what does this concept mean and what can be inferred'; OCOM answers 'what exists operationally and how is it governed'. An OCOM model can be expressed with an ontology, but an ontology does not, by itself, supply ownership, lifecycle or evidence.",
  "scope": {
    "compared": [
      "How each defines concepts, classes and properties",
      "How each treats meaning, reasoning and validation",
      "What each is fundamentally for"
    ],
    "notCompared": [
      "Specific languages (RDFS, OWL, SHACL) or reasoners",
      "Description-logic expressivity profiles",
      "Vendor triple stores or tools"
    ]
  },
  "mappings": [
    {
      "ocom": "Object",
      "target": "Class / Individual",
      "equivalent": "Partial"
    },
    {
      "ocom": "Classification",
      "target": "Class, subClassOf",
      "equivalent": "Similar"
    },
    {
      "ocom": "Relationship",
      "target": "ObjectProperty",
      "equivalent": "Similar"
    },
    {
      "ocom": "Metadata",
      "target": "DatatypeProperty / Annotation",
      "equivalent": "Similar"
    },
    {
      "ocom": "Constraint",
      "target": "Axiom / SHACL shape",
      "equivalent": "Partial"
    },
    {
      "ocom": "Identity",
      "target": "IRI",
      "equivalent": "Partial"
    },
    {
      "ocom": "Ownership",
      "target": "—",
      "equivalent": "None"
    },
    {
      "ocom": "Lifecycle",
      "target": "—",
      "equivalent": "None"
    },
    {
      "ocom": "Evidence",
      "target": "Provenance annotations",
      "equivalent": "Partial"
    }
  ],
  "differences": [
    {
      "aspect": "Purpose",
      "ocom": "Governs operational objects and their reality",
      "target": "Formalises meaning so machines can infer"
    },
    {
      "aspect": "Nature",
      "ocom": "An operating model with rules and conformance",
      "target": "A logical theory of a domain"
    },
    {
      "aspect": "Reasoning",
      "ocom": "Validation and conformance",
      "target": "Inference and entailment"
    },
    {
      "aspect": "Governance",
      "ocom": "First-class: ownership, policy, contract",
      "target": "Not defined by the model"
    },
    {
      "aspect": "Lifecycle",
      "ocom": "First-class: objects have states over time",
      "target": "Not defined by the model"
    }
  ],
  "capabilities": [
    {
      "capability": "Identity",
      "ocom": "Covered",
      "target": "Covered"
    },
    {
      "capability": "Relationships",
      "ocom": "Covered",
      "target": "Covered"
    },
    {
      "capability": "Classification",
      "ocom": "Covered",
      "target": "Covered"
    },
    {
      "capability": "Metadata",
      "ocom": "Covered",
      "target": "Covered"
    },
    {
      "capability": "Formal inference",
      "ocom": "Out of scope",
      "target": "Covered"
    },
    {
      "capability": "Constraints / validation",
      "ocom": "Covered",
      "target": "Covered"
    },
    {
      "capability": "Lifecycle",
      "ocom": "Covered",
      "target": "Out of scope"
    },
    {
      "capability": "Governance",
      "ocom": "Partial",
      "target": "Out of scope"
    },
    {
      "capability": "Ownership",
      "ocom": "Covered",
      "target": "Out of scope"
    },
    {
      "capability": "Provenance / Evidence",
      "ocom": "Partial",
      "target": "Partial"
    }
  ],
  "interoperability": [
    "An OCOM model may be expressed as an ontology; its terms map to classes and properties, and OCOM already publishes its vocabulary as machine-readable JSON-LD.",
    "An ontology may describe OCOM's vocabulary and add inference, but does not by itself supply ownership, lifecycle or governance.",
    "The recommended composition is to use an ontology for shared meaning and reasoning as one projection of an OCOM model, not as a replacement for it."
  ],
  "references": [
    {
      "label": "OCOM Object",
      "url": "/vocabulary/object"
    },
    {
      "label": "OCOM Classification",
      "url": "/vocabulary/classification"
    },
    {
      "label": "OCOM Constraint",
      "url": "/vocabulary/constraint"
    },
    {
      "label": "RDFS, OWL and SHACL ontology languages",
      "url": null
    }
  ],
  "canonical": "https://ocom.uno/comparisons/ontology",
  "url": "https://ocom.uno/comparisons/ontology",
  "coverageScale": [
    "Covered",
    "Partial",
    "Out of scope"
  ],
  "coverageNote": "Covered: the model defines the concept explicitly. Partial: the concept appears indirectly or by convention. Out of scope: the model does not set out to describe it; a boundary, not a deficiency. Three OCOM cells read Partial rather than Covered because the specification's own register records the gap: Evidence (AO-021), Governance (AO-023) and AI retrieval (AO-048). Workflow and Event are defined normatively at the Models tier without a Core Vocabulary term record."
}