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RE: [higgins-dev] Representing Metadata in the Higgins Ontology

> 
> It doesn't look like we're labeling anything specifically as metadata.  We
> just define a new object property, create a class for it's range, set it's
> domain(s) and that appears to be it.  This seems to require that the
> implementor of an IdAS CP will have to have a table that says ... for
> example, "timeSpan" is metadata, not an attribute.  Is this correct?

You're right that the word "metadata" isn't explicitly used anywhere in
higgins.owl. The semantics of this word are defined by the IdAS API/CPI.

>From the RDF/OWL perspective, we could create a consistent (with IdAS)
definition of higgins:Attribute metadata as:

  any RDF property whose domain is higgins:Attribute and which is 
  neither "higgins:complexValue" nor "higgins:simpleValue".  

And we could define higgins:DigitalSubject metadata as:

  any RDF property whose domain is higgins:DigitalSubject and which
  is neither "higgins:attribute" nor "higgins:relationship"

BTW, I'd have to ask Jim if he thought we should also exclude
"higgins:uniqueIdentifier" or not.

And we could define higgins:SubjectRelationship metadata as:

  any RDF property whose domain is higgins:SubjectRelationship
  and which is neither higgins:contextURI nor higgins:subjectCUID 

> 
> I'm trying to define some metadata for a derived ontology we're working on
> and I feel like, especially for derived ontologies, we'll need to
> specificall call things out as metadata.  Of course, I may just be out in
> left field here, so let me give the specific example ... of course, this
> may just be an extension of the Relationship vs. Attribute discussion but
> hey, I'm trying to make progress where I can ...

Let me know what you think of the above. If that doesn't work for you, you
can define your own concept (RDF property) in your sub-ontology and create
sub-properties from that. And if that doesn't work, there are other
options...

> 
> I want to define an object property, as far as I can tell, as a
> subProperty of a &higgins;relationship. 

You can certainly define a sub-property of higgins:relationship, but I would
have thought that its range would be a subclass, C, of
higgins:SubjectRelationship. And I would have thought that it is instances
of C that are the places where you can hang all kinds of RDF properties
(much like our postalAddress example).

BTW, on a related note. I'm still open to changing higgins.owl such that the
higgins:SubjectRelationship is a sub-class of higgins:Attribute as we
discussed last Thursday. Doing so would, through inheritance, give
SubjectRelationship (optional) "metadata" properties such as source,
timeSpan, etc. Would that also help?

 I want my object property to have
> metadata and, as per the IdAS API, a relationship can have metadata.
> That's good.  What do I need to do in my ontology to define this metadata,
> identify it as metadata, and restrict it to the object property I desire?

Let me know what you think of what I've written above, before I try to
answer further.


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