Issue 134Metamodel for OWL 2

Peter Haase, Elisa Kendall, Boris Motik, Evan Wallace

Current Structural Specification

• Comes with set of UML diagrams

• Intended to be compatible with MOF

MOF Metamodel for More Preciseness

• Precise definition of structural specification

• Example: Declaration rules

• Formal definition of structural consistency possible

• Lack of such a specification lead to a lot of confusion in OWL 1

Advantages of a MOF Metamodel for OWL 2

• More preciseness in the structural specification (via OCL constraints)

• Machine-processable serialization of the specification

• Reuse of existing MOF tooling – E.g. automated generation of APIs, editors,

etc.

• Possibility of specifying UML Profiles (visual syntax for ontologies)

UML Diagram of MOF Metamodel

Integrity constraint:self.versionURI != 0 implies self.ontologyURI != 0

Metamodel Tooling

Concrete Proposal

• Make the use of MOF for the structural specification explicit by:

1) stating that the UML diagrams in the Structural Syntax document are consistent with a MOF compliant specification of the structural syntax

2) potentially adding a machine-readable serialization and high-level documentation of a MOF metamodel for OWL 2 as an additional document

Possible Future Work within ODM WG of the OMG

• Normative definition of OWL 2 metamodel, including– Extended descriptions of the metamodel– Provision of UML profiles– Alignment with other (existing) metamodels

• Alignment will be easier if structural specification of OWL 2 already provided as metamodel

• The OMG ODM WG therefore supports the definition of a first metamodel within the W3C OWL WG