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Help on RDF model design

From: Andrew Kuchling <akuchlin@mems-exchange.org>
Date: Fri, 31 May 2002 11:53:40 -0400
To: www-rdf-interest@w3.org
Message-Id: <E17Doii-0007mS-00@ute.mems-exchange.org>

I'm trying to learn how to design RDF models, and am starting with a
simple one for book reviews.  Can someone please critique the approach
taken here, and point out bad design decisions, or principles that
should be followed?

Here's the basic model. A resource R can be stated to be a review of
resources T1, T2, T3.  (You might be reviewing three new books, or all
the titles in a series.)  Reviews have the following properties:

  Items -> a list of resources T1, T2, T3, ...
  Author -> string
  Date -> string 
  
The resources T1, T2, ... should then each have a title and author.
(A real application would likely use Dublin Core for this, of course.)
A sample RDF file in this model would then look like this:

<rdf:RDF xmlns:rdf="..." xmlns:rev="...">
  <rdf:Description 
    about="http://..."
    rev:date="1999-04-14" rev:author="A.M. Kuchling"
    rev:items="urn:isbn:123456789" />

  <rdf:Description about="urn:isbn:123456789" 
     rev:author="Bob Brier"
     rev:title="The Encyclopedia of Mummies" />

 </rdf:RDF>

Q1. Are there common principles for model design that should be followed?
(Pointers to articles/papers would be greatly appreciated.) Does this
simple model break any of them?

Q2. rev:author is here given as a human-readable string.  It could
also be given as a URI, if someone were to assign URIs to people (say,
authors or mummy researchers or Virginia residents).  Must the book
review model state its expectation of the property value, whether it's
a URI or an arbitrary string?  Can the model support both
possibilities, and if so, how?  Or do you need to have two distinct
properties in this case, i.e. rev:author="Bob Brier" and
rev:authorURI="http://people.org/..."

Q3. If a review covers multiple resources, the value of the items
property would have to be an RDF Bag or Sequence.  (RDF's Alternative
doesn't make sense here.)  Should the model specify which type is
expected?

Thanks in advance...

--amk                                                             (www.amk.ca)
"As an historian, I simply don't believe in coincidence."
    -- Robertson Davies, _The Manticore_
Received on Friday, 31 May 2002 11:54:23 GMT

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