The DBpedia Ontology is a shallow, cross-domain ontology, which has been manually created based on the most commonly used infoboxes within Wikipedia. The ontology currently covers 685 classes which form a subsumption hierarchy and are described by 2,795 different properties.
With the DBpedia 3.2 release, we introduced a new infobox extraction method based on hand-generated mappings of Wikipedia infoboxes to the DBpedia ontology. The mappings defined fine-granular rules on how to parse infobox values. The mappings also addressed weaknesses in the Wikipedia infobox system, like having different infoboxes for the same class, using different property names for the same property, and not having clearly defined datatypes for property values. Therefore, the instance data within the infobox ontology is much cleaner and better structured than the infobox data within the DBpedia infobox dataset which was generated using the old infobox extraction code.
With the DBpedia 3.5 release, we introduced a public wiki for writing infobox mappings, editing existing ones as well as editing the DBpedia ontology. This allows external contributors to define mappings for the infoboxes they are interested in and to extend the existing DBpedia ontology with additional classes and properties.
Since the DBpedia 3.7 release, the ontology is a directed-acyclic graph, not a tree. Classes may have multiple superclasses, which was important for the mappings to schema.org. A taxonomy can still be constructed by ignoring all superclasses except the one that is specified first in the list and is considered the most important.
See also the mapping statistics.
The DBpedia Ontology currently contains about 4,233,000 instances. The table below lists the number of instances for several classes within the ontology:
The DBpedia Ontology is provided for download in four parts:
- DBpedia Ontology T-BOX (Schema)
- DBpedia Ontology A-Box RDF type statements (Instance Data)
- DBpedia Ontology A-Box RDF object relations (Instance Data)
- DBpedia Ontology A-Box RDF literal facts (Instance Data)
- DBpedia Ontology A-Box RDF specific properties (normalized units) (Instance Data)