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Re: Cambridge Communique

From: Pierre-Antoine CHAMPIN <champin@cpe.fr>
Date: Fri, 12 Nov 1999 10:44:16 +0000
Message-ID: <382BEF80.B9CAA7BA@cpe.fr>
To: www-rdf-interest@w3.org
Ken Laskey wrote:
> >My understanding is the an RDF schema is a specification for data (like a
> >database schema) while an XML schema is specification for a language syntax.
> >The two things are similar but distinct.

I much agree with that,
except that RDF schema is originally a specification for META-data

> Here is another opinion of the relationship.  Imagine an XML Schema
> that defines the "hard" metadata for a book, e.g. author, title,
> ISBN.  These are immutable properties of the book.  Now, the New York
> Times does a review of the book which creates "assertions" which are
> not hard facts but still related information.  The connection of
> these assertions to the book would be through RDF.  RDF might also be
> used by various booksellers to make assertions about the price they
> are individually charging or possibly special offers about the book.

There is something much more primitive about it :
not everything is written in XML - at least not yet ;P ...
So RDF is useful to describe metadata about GIFs, JPGs,
or any XML document you can't modify...

Another problem is that wether or not you can modify it,
a resource often contains metadata about itself, in its own format.
So it's been natural, when writing DTDs or XML-schemas,
to include TAGs for describing metadata (author, ISBN, etc.)

And those metadata are 'hard' in the sense that they are the most
trustable, since they are written by the author herself !

Now that we have RDF,
when we intend to include metadata in our documents (or elsewhere!)
it looks reasonnable to use RDF rather than reinvent a metadata language.

  Pierre-Antoine
Received on Friday, 12 November 1999 05:24:32 GMT

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