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Re: Annotations use case

From: Jim Hendler <hendler@cs.umd.edu>
Date: Wed, 12 Feb 2003 08:23:30 -0500
Message-Id: <p05200f12ba6ff97c4213@[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 9:44 +0000 2/12/03, Ian Horrocks wrote:
>Another point on annotation.
>
>I presume that it is obvious by now that we need to have annotations
>in the RDF graph (XML comments just don't hack it as there is no
>guarantee that they would be preserved when exchanging or editing
>ontologies).

No, I think we agreed that we need to have annotations in the RDF 
Graph.  I wouldn't agree to the parenthetical, but don't think it is 
germane.

>  If all such comments are semantically meaningful, then
>there is a serious issue with backwards compatibility. E.g., if I
>correct a spelling mistake in an annotation, then is the resulting
>ontology backwards compatible with the original?

No, there is no problem w/backwards compatibility -- if you change an 
annotation you change the document -- how is the computer to tell a 
significant from an insignificant change?  If no annotations count, 
you cannot address the use cases that started this thread (and Ian, 
with due respect, you've just ignored them - how *would* you handle 
the "embarass" case whcih I remind you, is an ability our 
requirements necessitate)

So fixing a spelling mistake may sound absurd, but consider if I have 
a web page that points to
  http://www.w3.com/.../owl
and change it to
  http://www.w3.org/.../owl
I've made a real change to the site and, for example, a crawler 
revisiting my site is likely to change a number of things based on 
this.  We have a good solution to your problem -- when you fix the 
comments, you add that your new version is backwards-compatible with 
your old version so people know nothing contentive has changed.

Look, I realize there is a real issue here - we have comments that we 
want to have meaning on (my embarass case) and comments we don't 
(Ian's preferred solution).  One solution is that you only use 
rdfs:comments for those things that you want to have meaning on, and 
use xml comments on things that are illustrative.  Ian doesn't like 
this. Ian, can you make a suggestion that can handle both contentive 
and non-contentive comments -- just ignoring the use cases for 
contentive comments won't make them go away
  -JH


>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
Received on Wednesday, 12 February 2003 08:23:46 GMT

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