Statements
Instances of this class model semantic triples (subject, predicate, object) and corresponding qualifiers. Every edge in the knowledge graph corresponds to a statement instance.
Note
Note: For technical reasons for every Statement instance there exits a dual
Statement instance. For most situations this does not matter, though.
The whole knowledge graph is a collection of Entities (Items, Relation, Literals) and
Statements. Roughly speaking, the collection of Entities defines what exists (in the
respective universe of discourse) while the collection of Statements defines how these
things are related. Because flat subject-predicate-object triples have very limited
expressivity it is possible to “make statements about statements”, i.e. use
a Statement instance as subject another triple.
This Wikidata
-inspired mechanism is called qualifiers (see next page).