This section last edited on DateTime() is part of the ["SKOS/Reference"] wiki draft.
Section: Semantic (Paradigmatic) Relations
This section defines the vocabulary and formal semantics for the SKOS Semantic Relation Properties.
The SKOS Semantic Relation Properties are defined informally in the SKOS Primer.
Vocabulary
skos:semanticRelation skos:broader skos:narrower skos:related |
Semantic Conditions
skos:semanticRelation, skos:broader, skos:narrower and skos:related have type Object Property. |
The Domain and Range of skos:semanticRelation is skos:Concept. |
skos:broader, skos:narrower and skos:related are Sub-Properties of skos:semanticRelation. |
skos:broader and skos:narrower are Inverse Properties. |
skos:related is a Symmetric Property. |
skos:related is disjoint with the transitive closure of skos:broader. |
Examples
The graph below is Consistent.
ex:foo skos:broader ex:bar . ex:foo skos:related ex:baz .
The graph below is Inconsistent, because there is a "clash" between skos:related and skos:broader.
ex:foo skos:broader ex:bar . ex:foo skos:related ex:bar .
The graph below is Inconsistent, because there is a "clash" between skos:related and the transitive closure of skos:broader.
ex:foo skos:broader ex:bar . ex:bar skos:broader ex:baz . ex:foo skos:related ex:baz .
The graph below is Inconsistent, again because there is a "clash" between skos:related and the transitive closure of skos:broader, which can be inferred from the semantic conditions stating that skos:broader and skos:narrower are Inverse Properties, and that skos:related is a Symmetric Property.
ex:foo skos:narrower ex:bar . ex:bar skos:narrower ex:baz . ex:foo skos:related ex:baz .
Notes
Note that no semantic conditions are given concerning the transitivity of skos:broader. Interpreting skos:broader as a Transitive Property would be consistent with the SKOS semantics. Alternatively, interpreting skos:broader as an Intransitive Property would also be consistent with the SKOS semantics.
Note that no semantic conditions are given concerning the reflexivity of skos:broader. Interpreting skos:broader as a Reflexive Property (every SKOS Conceptual Resource is broader than itself) would be Consistent with the SKOS semantics. Alternatively, Interpreting skos:broader as an Irreflexive Property (no SKOS Conceptual Resource is broader than itself) would also be Consistent with the SKOS semantics.
Note that no semantic condition is given concerning the reflexivity of the transitive closure of skos:broader. This means that a graph containing a cycle involving skos:broader is not Inconsistent with the SKOS semantics. However, interpreting the same graph as an Inconsistency is not prohibited by the SKOS semantics either, and might be useful in many situations.
This flexibility in the formal interpretation of the SKOS Semantic Relation Properties has been chosen to allow different design patterns to be explored for using SKOS in combination with more formal languages such as OWL, and for using SKOS with different query expansion algorithms in information retrieval systems.