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Re: Annotations use case

From: Jim Hendler <hendler@cs.umd.edu>
Date: Sat, 8 Feb 2003 19:20:55 -0500
Message-Id: <p05200f58ba6b4e29f01b@[10.0.1.3]>
To: Ian Horrocks <horrocks@cs.man.ac.uk>
Cc: Mike Dean <mdean@bbn.com>, webont <www-webont-wg@w3.org>

At 0:04 +0000 2/9/03, Ian Horrocks wrote:
>On February 7, Jim Hendler writes:
>>
>>  At 7:42 -0800 2/7/03, Mike Dean wrote:
>>  >  > and recommends use of XML comments instead - ugly, but I 
>>could live with)
>>  >
>>  >This is problematic in that XML comments aren't preserved in
>>  >the RDF graph.  It precludes round-tripping of content.
>>  >
>>  >	Mike
>>
>>  no, no, no - that's my whole point!  - things one wants in the graph
>>  go in RDFS:comment -- i.e. you need them to round trip.  Things one
>>  adds as "comments" in the traditional programming language sense
>>  should be lost (i.e. when you roundtrip C code the comments are lost)
>>  and thus should be in XML comments instead!
>
>The C code metaphor is not valid - the "exchange syntax" for C
>programs is the source text, including comments, and not the compiled
>code. It would not be acceptable if comments were stripped out by
>tools (such as editors) that work with C source code.

yes, but out exchange syntax is the RDF/XML, and there's no reason 
one would strip the comments out if sending that -- however, if 
parsing that into a graph and then dumping the graph back to RDF, you 
would lose the XML comments - as would be expected - you wouldn't 
lose the rdf:comments because someone went to the trouble to put them 
in the graph - so things that work with our "source code" (RDF/XML) 
wouldn't strip the comments out, but "compiling/decompiling" C would 
strip out commments


(note too that we rejected the idea of roundtripping as a requirement 
quite long ago [see minutes of ftf2 - Amsterdam] - the decision was 
to send a pointer to the original document if it was important for it 
to be seen in original form - so that would work for XML as well)

>Using XML comments raises all sorts of issues and seems to be in
>conflict with declaring RDF to be the exchange syntax. It isn't easy
>to see how XML comments would be handled by an editor, and how they
>would be associated with different elements of an ontology. It is
>certainly very unlikely that all tools would do this in a uniform way,
>so we would loose any real tool interoperability - how acceptable
>would it be if any time I use a different ontology editor I
>loose/trash all the comments in my ontology (consider the C
>programming analogy)?


again, my point was to emphasize that rdf:comments should NOT be 
stripped out.  However, comments that didn't effect the graph would 
live in the source document

>
>Just look at some of the things that are typically done with comments
>(e.g., in the DAML+OIL ontology library, where they are often used to
>attach natural language rubrics to classes) and ask yourself (a) if
>this could be done using XML comments (while maintaining tool
>interoperability), and (b) if it is appropriate that such comments
>affect entailment in the ontology language.

exactly, if I attach different natural language to two different URIs 
they are NOT the same (see my "embarass" example) - that's my main 
point.

So I guess we are agreeing :->

>
>Ian
>
>>
>>  --
>>  Professor James Hendler				  hendler@cs.umd.edu
>>  Director, Semantic Web and Agent Technologies	  301-405-2696
>>  Maryland Information and Network Dynamics Lab.	  301-405-6707 (Fax)
>>  Univ of Maryland, College Park, MD 20742	  240-731-3822 (Cell)
>>  http://www.cs.umd.edu/users/hendler
>>


-- 
Professor James Hendler				  hendler@cs.umd.edu
Director, Semantic Web and Agent Technologies	  301-405-2696
Maryland Information and Network Dynamics Lab.	  301-405-6707 (Fax)
Univ of Maryland, College Park, MD 20742	  240-731-3822 (Cell)
http://www.cs.umd.edu/users/hendler
Received on Saturday, 8 February 2003 19:21:15 GMT

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