Re: rdf inclusion

   [Dave Rager]
   I'm willing to add daml:imports statements to the SONAT data files 
   since this seems to be the proper usage of DAML+OIL.

   Since I had never seen daml:imports used in this way, I checked a few 
   random  DAML+OIL instance files from homework 3 and the crawler.  I 
   didn't see any that use daml:imports as Jeff described.  I did find:

   a) daml:imports used in daml:Ontology header in the instance file, 
   even though there are no ontology definitions in the file.

   b) daml:imports used in a header tag describing the file:
   <rdf:description rdf:about="">
	<daml:imports>...</daml:imports>
   </rdf:description>

   c) No use of daml:imports

   Does someone want to define the scope of the daml:imports statement. 

Jeff or someone else probably knows the official answer to this
question, but what I would recommend is:

 - Make (a) illegal (unless I'm missing something)
 - In case (b), where the convention about="" indicates that we're
   talking about this very document, the ontology should apply to the
   entire document.

      [Dave]
      If it is applied to a document as in b) do all DAML+OIL resources 
      referenced within that document also use the imported ontology?  Or 
      just to statements about the document itself?

   Obviously, the first interpretation is much more useful.  Perhaps
   we can resolve the issue by saying that what the document imports
   *is* a statement about the document itself.  (Possible
   philosophical minefield here.)

 - However, there is also case (b'):
      <rdf:description rdf:ID="me">
	   <daml:imports>Ontology FOO</daml:imports>
           <FOO:property>value</FOO:property>
      </rdf:description>

   where ontology FOO is imported for the purpose of describing an
   otherwise unknown entity whose url ends in ...#me .  (I've left out
   the namespace stuff you would also need.)

   Here the ontology applies only to the given description.

Some quick clarification of these issues would be useful, because we
are bringing an ontology-mapping server up online in the near future,
and we wouldn't want to start off on the wrong foot.

                                             -- Drew McDermott

Received on Monday, 22 April 2002 21:20:01 UTC