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Re: Lack of RDF/XML examples in new standards

From: Stephen Bounds <km@bounds.net.au>
Date: Wed, 12 Nov 2008 22:42:59 +1100
Message-ID: <491AC143.8090403@bounds.net.au>
CC: SKOS <public-esw-thes@w3.org>

Jakob & Norman,

I'm going to try and have my cake and eat it too, I'm afraid.

*Yes*, RDF/XML can be a very confusing syntax, particularly if you nest 
multiple levels of assertion deep, don't do predicate striping, etc etc.

But if you limit yourself to simple subject-predicate-object assertions, 
RDF/XML provides a syntax that is very familiar to XML authors with the 
added benefits of RDF semantics.

Not coincidentally, this is exactly what the SKOS examples showed.  A 
typical SKOS document looks like this:

<rdf:RDF>
   <skos:Concept rdf:about="http://www.example.com/foo#bar">
     <skos:prefLabel>bar</skos:prefLabel>
     <skos:broader rdf:resource="http://www.example.com/foo#baz" />
   </skos:Concept>

   <skos:Concept rdf:about="http://www.example.com/foo#baz">
     ...
   </skos:Concept>

   <skos:Concept rdf:about="http://www.example.com/foo#qux">
     ...
   </skos:Concept>
</rdf:RDF>

which essentially boils down to a sequence of assertions that are either:

   Subject -> Predicate -> Literal, or
   Subject -> Predicate -> Resource

This covers 99% of the needs of basic SKOS users, and this limited form 
of RDF/XML is both correct and easily understandable by non-RDF literati.

A personal example: I found SKOS RDF/XML to be a really useful 
intermediate language for capturing thesaurus-type relationships.  The 
initial XML was created using a Perl XML builder library from a CSV source.

I then transformed the data into static web pages using an XSL transform 
tool (Saxon), and as a dynamic web application through ingest and 
manipulation via an XML database platform (eXist).

I looked at RDF tools (Jena etc), but couldn't find anything that had 
close to the same maturity or ease of use of these XML tools.

Perhaps this was just my existing familiarity with XML rather than RDF, 
but that too is kind of my point.  The pool of XML developers is far 
larger than the pool of RDF developers.

Cheers,

-- Stephen.

Jakob said:
> RDF/XML is one of the main reasons why adoption of RDF took so long.
> There are dozens of ways to encode the same graph in RDF/XML. Without a
> full specialized parser you are lost. RDF/XML might be more known and it
> *looks* more easy but it confuses more then it helps.

Norman Gray wrote:
> Good heavens!  I would _never_ show a beginner RDF/XML.  Do you really 
> do this?
Received on Wednesday, 12 November 2008 11:43:43 UTC

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