Scope
Compared
- How each represents entities, relationships and identity
- How each treats provenance and evidence
- What each is fundamentally for
Not compared
- Specific serializations (RDF, property graphs) or query languages (SPARQL, Cypher)
- Storage engines or performance characteristics
- Vendor implementations
Terminology mapping
| OCOM | Knowledge Graph | Equivalent |
|---|---|---|
| Object | Entity | Partial |
| Relationship | Edge | Similar |
| Identity | Node identifier | Partial |
| Metadata | Properties | Similar |
| Reference | Edge / IRI | Partial |
| Ownership | — | None |
| Lifecycle | — | None |
| Evidence | Provenance | Partial |
Conceptual differences
| Aspect | OCOM | Knowledge Graph |
|---|---|---|
| Purpose | Governs operational objects and their reality | Represents knowledge as entities and relationships |
| Nature | An operating model with rules and conformance | A data structure for facts |
| Governance | First-class: ownership, policy, constraint, contract | Not defined by the model |
| Lifecycle | First-class: objects have states over time | Not defined by the model |
Concept coverage
| Concept | OCOM | Knowledge Graph |
|---|---|---|
| Identity | Covered | Covered |
| Relationships | Covered | Covered |
| Metadata | Covered | Covered |
| Lifecycle | Covered | Out of scope |
| Governance | Partial | Out of scope |
| Ownership | Covered | Out of scope |
| Provenance / Evidence | Partial | Partial |
| AI retrieval | Partial | Covered |
Three OCOM cells read Partial rather than Covered (Governance, Provenance / Evidence, AI retrieval), and the reason for each is recorded in the specification's own register: Governance is a Core Characteristic of every Object that no document defines as one (AO-023); Evidence has no Meta, Models or Language definition, its Definition being reserved for a future version (AO-021); AI retrieval is disclaimed by AI/Context/Context Assembly.md, which prescribes no retrieval algorithms (AO-048). Workflow and Event are defined normatively at the Models tier and carry no Core Vocabulary term record.
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.
Interoperability
- An OCOM model may be represented as a Knowledge Graph; OCOM already publishes its own graph as JSON-LD.
- A Knowledge Graph may store OCOM objects and relationships, but does not itself provide governance, lifecycle or ownership.
- The recommended composition is to use a Knowledge Graph as one projection of an OCOM model, not as a replacement for it.
References
- OCOM Object
- OCOM Relationship
- OCOM Reference
- RDF and property-graph knowledge-graph models