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Re: Issue 5.17 XML presentation syntax for OWL

From: Jeff Heflin <heflin@cse.lehigh.edu>
Date: Mon, 16 Dec 2002 15:37:15 -0500
Message-ID: <3DFE397B.59348D72@cse.lehigh.edu>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
CC: www-webont-wg@w3.org

Peter,

I've finally had a chance to look at your XML presentation syntax in
detail. In general, it looks very good. However, I have a few
suggestions:

1) I agree with Masahiro that it is odd to have SubClassOf as a child of
Ontology, especially since there is an alternative way to represent the
same information. 

2) I think the implicit intersectionOf that is used for multiple
descriptions is bound to lead to confusion. Perhaps this could be fixed
by limiting a Class to at most one description? This will force people
to explicitly use the intersectionOf or unionOf as appropriate.

3) Is EnumeratedClass necessary? Doesn't a Class with a OneOf do the
same thing?

4) Why have SubPropertyOf as a subelement of Ontology? You have a super
attribute in ObjectProperty and DataProperty that does the same thing.

5) Can we change DatatypeProperty and ObjectProperty to Property, with
an attribute to distinguish between the two? We could make Object the
default value for this attribute.

6) Can we change the EquivalentClasses, EquivalentProperties, and
SameIndividual elements (which are are currently subelements of
ontology) to subelements of Class, Property, and Individual,
respectively?

7) Do we really need to distinguish between DataRestrictions and
IndividualRestrictions? Let's just call them Restrictions.

8) The use of cardinality attributes with Restrictions that have
subelements is confusing. It could be mistakenly interpreted to mean the
same thing as the use of cardinalityQ in DAML+OIL. Perhaps it would be
clearer to change the cardinality attributes to elements.

9) How about changing all element and attribute names to start with
lower case characters? The OWL exchange syntax capitalization looks
funny here.

10) Finally, I do not think Ontology is a suitable top-level element for
documents that contain only instances. This is the same discussion that
we got into a few weeks ago, and as I understand it, the guide is going
to have specific terminology for distinguishing between "ontology"
documents and other documents. It will be very confusing for users of
the XML presentation syntax if the term ontology is used differently
than it is in the guide. I suggest we have owl as our root element, with
an ontology child and perhaps a data child.

Thanks again. If you like, I'd be happy to help get the XML presentation
syntax into suitable format for the appendix.

Jeff



"Peter F. Patel-Schneider" wrote:
> 
> I revised the XML Schema for an OWL presentation syntax that I sent around
> in June to make it correspond more closely with the current version of the
> OWL abstract syntax.  The Schema iself and an example are attached to this
> message.  As well, they are available at
>     http://www-db.research.bell-labs.com/user/pfps/owl/schema-2.xsd
>     http://www-db.research.bell-labs.com/user/pfps/owl/schema-2-example.xml
> 
> I propose that this XML Schema be used as the starting point for the the
> OWL XML presentation syntax.  I further propose that the final version of
> the XML Schema itself and at least one example be part of an appendix to
> the OWL Guide document.
> 
> Peter F. Patel-Schneider
> Bell Labs Research
>
Received on Monday, 16 December 2002 15:37:24 GMT

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