getting rdf files of rda ontology

[delahousse]

Working on a migration project to RDA, I cannot find the files describing rda ontology to upload in Protégé. Can you give me any help to identify this / those files.

[GordonDunsire]

The RDA ontology is specified in a set of RDF files. These are categorized by the domain entity, with a separate file for entity classes. They can be found in the download subfolders for each serialization; for RDF/XML this is ../xml/

Within the subfolder, the properties and classes are in the ../elements/ subfolder; e.g. ../xml/elements/

Within the elements subfolder, the filename for each category of domain entity is given as the single-letter category code; e.g. ../xml/elements/a.xml is the RDFS file of 'canonical' RDA properties of the Agent entity (and its sub-types).

Within the elements subfolder there is a subfolder for each category that contains the OWL datatype and object files that complement the RDFS file of the category; e.g. ../xml/elements/a/object.xml is the file of OWL object properties for the Agent entity. The object files contain the declarations of owl:inverse relationships. The datatype and object files do not repeat definitions and scope notes of the 'canonical' properties, so the complete RDA ontology requires all of the categorized canonical, object, and datatype files; this is quite large because RDA covers string-based as well as thing-based bibliographic metadata :-)

[delahousse]

Thanks a lot for your detailed explanations
Jean

[diseminger]

For completeness, I'll add what I responded via email on April 4, which is very much the same thing that Gordon described:

The RDA Ontology is broken up to into several files for ease of use and updating.

The classes are defined in http://rdaregistry.info/Elements/c/ .

The properties are defined in:

Agent: http://rdaregistry.info/Elements/a/
Expression: http://rdaregistry.info/Elements/e/
Item: http://rdaregistry.info/Elements/i/
Manifestation: http://rdaregistry.info/Elements/m/
Nomen: http://rdaregistry.info/Elements/n/
Place: http://rdaregistry.info/Elements/p/
Timespan: http://rdaregistry.info/Elements/t/
Work: http://rdaregistry.info/Elements/w/
RDA Entity: http://rdaregistry.info/Elements/x/

These are the canonical properties. There are also sets of datatype and object properties, which are each subproperties of the canonical sets. These sets have namespaces which add on 'datatype' or 'object' to the canonical namespace, i.e http://rdaregistry.info/Elements/a/datatype, http://rdaregistry.info/Elements/a/object, etc.

The canonical properties declare a domain for each element, but do not declare a range. This allows for RDFS implementations of RDA where the value may either be a real world object or may be a literal. The range can be determined from the definition of the property.

The datatype and object properties, which are subProperties of the canonical properties, allow for OWL implementations of RDA. The range of the datatype properties are an rdfs:Literal; the range of the object properties are declared and are an RWO that is an RDA class. All of the canonical properties have a datatype subProperty. A canonical property only has an object subProperty if the range of the canonical element is intended to be an RDA class.

More in-depth explanations are provided in the Guide for Developers at https://www.rdaregistry.info/rgGuide/.