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Issue #horrocks-01 semantics of rdfs:comment

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Fri, 28 Feb 2003 22:24:50 +0000
Message-Id: <5.1.0.14.0.20030228222322.0a19c008@localhost>
To: Ian Horrocks <horrocks@cs.man.ac.uk>, www-rdf-comments@w3.org

Ian,

This comment has been recorded as:

   http://www.w3.org/2001/sw/RDFCore/20030123-issues/#horrocks-01

The RDFCore WG will consider it and respond in due course.

Brian

At 23:28 20/02/2003 +0000, Ian Horrocks wrote:

>I believe that the lack of "real" comments in RDF is a crucial
>omission that makes it unsuitable for use in realistic ontological
>engineering, or as as the basis for other languages (such as OWL) that
>will be so used.
>
>The point is this. RDF/OWL are supposed to be ontology languages, and
>users will (hopefully) want to use them to build ontologies. In many
>cases these will be large and complex, and will be worked on by many
>authors using many different tools. They will hopefully also be
>shared, extended etc. As in software engineering, the use of comments
>will be important in this ontology engineering process.
>
>Such comments are not intended to have any impact when the ontology is
>used in applications (in the same way that comments have no impact on
>code when it is compiled and run). In particular, it would be
>inappropriate for applications to infer semantic differences in
>information represented in two ontologies based solely on differences
>in comments (in the same way that it would be inappropriate for code to
>behave differently when only the comments are changed).
>
>It has been suggested within the WebOnt working group that the use of
>XML comments is the solution. This does not work, however, as XML
>comments would be stripped by RDF parsers, and so comments would be
>lost whenever an ontology goes through a read/write cycle, e.g., when
>being edited (if I can be forgiven for banging away at my software
>engineering metaphor, this would be equivalent to emacs stripping
>comments when editing source code). Moreover, there is no standard
>mechanism for indication which component(s) of the ontology an XML
>comment refers to.
>
>As comments are a "must have", implementors of ontology tools will be
>forced to adopt ad hoc solutions. This will severely impede tool
>interoperability. Tool interoperability is one of the main benefits
>that will encourage the initial uptake of language standards such as
>RDF and OWL, and lack of interoperability may cause potential users to
>look for solutions elsewhere.
>
>On the other hand, I can't see how making rdf:comments be "real"
>comments, i.e., have no semantic impact, would have any adverse effect
>on RDF.
>
>Regards, Ian
>--
>Ian Horrocks, Department of Computer Science,
>University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
>Tel: +44 161 275 6133  Fax: +44 161 275 6211  Email: horrocks@cs.man.ac.uk
>URL: http://www.cs.man.ac.uk/~horrocks
Received on Friday, 28 February 2003 17:23:59 GMT

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