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comment/question on OWL Reference

From: Benjamin Nowack <office@e-senses.de>
Date: Tue, 16 Sep 2003 15:26:24 +0200
To: public-webont-comments@w3.org
Message-ID: <PM-EH.20030916152624.2B544.2.1D@192.168.27.2>


Hi.

First of all I'd like to say that the various OWL 
documents (and their authors) do a great job in 
helping understand the underlying ontology concepts,
including non-scientists like me. I enjoyed the 
guide and could follow the reference quite well.
But now some questions arose that I couldn't find
an answer to in the reference:

The reference says that owl:Restriction is a subclass 
of owl:Class. I understand that every 
<owl:Restriction>
...
</owl:Restriction>
defines a separate class and must not have any 
subnodes other than onProperty and the corresponding
constraint. And usually a class is specified by not 
only one restriction but many of them. Therefore
it makes sense to combine property restrictions 
via axioms such as owl:subClassOf.

But does that mean that it is not _allowed_ to 
define a class like
<owl:Restriction rdf:Id="MyClass">
...
</owl:Restriction>

In 3.2.3 the Reference excludes owl:Restriction for
being used as a named class but in 3.1 (NOTE 3) it
is mentioned as a way to define complete classes 
(if I get it right).

Another thing is that the Reference and the Guide
give me the impression that it's best practice 
to serialize a class with multiple property 
restrictions by using multiple owl:subClassOf 
properties (and not a single owl:intersectionOf 
property instead). Is that true?

This may sound theoretical but it may have effects 
on the way an OWL editor should best serialize its
ontologies.

Thanks for your time,
Benjamin

___________________________
benjamin nowack

am exerzierplatz 1
D-97072 wuerzburg
Received on Tuesday, 16 September 2003 09:31:55 GMT

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