Major Influences on the Design of ODM Dan Chang (IBM) Elisa Kendall (Sandpiper) MDSW 2004

The OMG ODM RFP Specification of: MOF 2 compliant metamodel UML2 profile Any additional information To support: Development of ontologies using UML modeling tools Implementations of ontologies in OWL Forward and reverse engineering of ontologies

Benefits of ODM Forward engineering: development of ontologies using MOF based (e.g., UML) modeling tools breaking the knowledge acquisition bottleneck Reverse engineering: leveraging existing ontologies (e.g., in OWL) for ontology modeling solving the knowledge management challenge Integrated ontology / software development: making ontology development an integral part of software development

The ODM Architecture > UML2 > UML2 > DL > DL > SCL > SCL > TM > TM > OWL > OWL > RDFS > RDFS > ER > ER extension mapping Ontology Modeling Languages Ontology Description Languages NOTE: UML2 metamodel is an existing OMG standard UML Profiles for Ontology -- RDFS -- OWL -- TM UML Profiles for Ontology -- RDFS -- OWL -- TM UML Notations Ontology Logic Languages dependency Figure 1 ODM Architecture

Basic Considerations MOF2 is the meta metamodel (vs. RDF Schema is the meta metamodel for RDF Schema and OWL) Direct support for forward and reverse engineering (e.g., generation of OWL files and APIs) no abstract subset or superset metamodel

Issue #1: Objectives of ODM 8 of 22 requirements: Support ontologies expressed in description logics (e.g., OWL DL) and higher order logics (e.g., OWL Full) Represent complex objects as aggregations of parts Support multiple inheritance of complex types … Support interoperation with other MOF and UML- based tools, including, for example, forward and reverses engineering of ontologies

Issue #2: What is Ontology Definition from the ODM RFP: Defines the common terms and concepts (meaning) used to describe and represent an area of knowledge Can range from a Taxonomy to a Thesaurus to a Conceptual Model to a Logical Theory

Issue #3: UML Profiles vs. Metamodels Metamodels To precisely represent the abstract syntax of target ontology definition languages UML mappings To leverage existing UML models and ontologies UML profiles To facilitate the use of UML notation (and tools) for ontology modeling

Issue #4: UML Extensions vs. New Metamodels New metamodels Simpler: UML2 metamodel is extremely complex Avoid unnecessary dependencies: UML2 metamodel is still evolving

Issue #5: Subclassing vs. Mapping Subclassing OWL metamodel subclassing from RDFS metamodel Mapping All others ??? RDFS as a common core metamodel

Issue #6: Namespaces and Names Name prefixes to simulate namespaces RDF RDFS OWL