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httpRange-14: Use Case for RDF

From: David Wood <dwood@softwarememetics.com>
Date: Mon, 5 Sep 2005 16:53:51 -0400
Message-Id: <6F9F6968-CB73-427A-8682-AF9AB0F2E9C2@softwarememetics.com>
To: public-swbp-wg@w3.org

Hi all,

This message suggests a use case for SemWeb URIs to be resolved via  
303 responses.  David Booth, Ralph Swick and I contributed.

This message is in response to the following action item:  "Ralph,  
DavidW, and DavidB to an initial draft of TAG httpRange-14 resolution  
impact on semweb application developers" [1].

Use Case:

A SemWeb application includes RDF data.  The application allows each  
URI in the RDF to be resolved, and possibly grounded in the Web.   
Information regarding those URIs may be found as follows:

   Following the TAG's resolution of httpRange-14 [2]:
   - Resolution may be attempted for any HTTP URI (an RDF subject,  
predicate or object).
   - Resolution of an HTTP URI resulting in a 2xx response determines  
that the nature of the resource identified by that URI is an  
information resources;
   - Resolution of an HTTP URI resulting in a 4xx ("error") response  
determines that the nature of the resource identified by that URI is  
unknown.

   Extending the resolution of httpRange-14:
   - Resolution of an HTTP URI resulting in a 303 ("see other")  
response determines that the nature of the resource identified by  
that URI may be determinable by redirection.  That is, the URI  
contained in the 303 response may be resolvable on the Web.
     o If the URI returned in the 303 response is resolvable,  
resolving that URI would result in an information resource describing  
the original RDF URI (either in human- or machine-readable form).   
The SemWeb application should treat the RDF URI as known and may  
optionally resolve the URI in the 303 response to obtain information  
regarding it.  The server returning the 303 response is, in effect,  
saying, "I'll confirm the existence of that name, and provide a  
pointer to more information regarding it".
     o If the 303 response does not contain a URI (or the URI is not  
resolvable), then the SemWeb application should treat the RDF URI as  
known, but accept that further information regarding it is not  
available.  The server returning the 303 response is, in effect,  
saying, "I'll confirm the existance of that name, but nothing more  
about it".
   - Resolution of HTTP URIs resulting in 4xx ("error") responses  
should be treated by SemWeb applications as determining that no  
information is known about the URI.  That is, the RDF URI is  
unknown.  The server returning the 404 response is, in effect,  
saying, "No such name exists".


Example:

An RDF statement includes a predicate, http://purl.org/dc/elements/ 
1.1/creator.  Resolution of that URI results in a 303 response.  The  
303 response includes a URI, http://dublincore.org/2003/03/24/ 
dces#creator.  A SemWeb application can determine that the predicate  
is known and that further information regarding it is available at  
the second (dublincore.org) URI.

Comments welcome!  Any errors in this message are mine; Ralph and  
David have not yet reviewed my summary.

[1] http://www.w3.org/2005/06/27-swbp-minutes.html#action02
[2] http://lists.w3.org/Archives/Public/www-tag/2005Jun/0039.html

Regards,
Dave
Received on Monday, 5 September 2005 20:54:04 GMT

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