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RE: Cool URIs, the Semantic Web and Everything

From: Hausenblas, Michael <michael.hausenblas@joanneum.at>
Date: Fri, 21 Dec 2007 09:23:00 +0100
Message-ID: <768DACDC356ED04EA1F1130F97D2985201449E42@RZJC2EX.jr1.local>
To: "Leo Sauermann" <sauermann@dfki.uni-kl.de>
Cc: <semantic-web@w3.org>, "Leo Sauermann" <leo.sauermann@dfki.de>


Leo,

Thank you for taking the time. Please see also my answer to Richard [1].

So, you gave an answer to my question. As, I did not read any other
comment
from someone else (e.g. the TAG :), I assume your explanation is the
'official',
good one. 
 
However, when you say  '"Cool uris" is about URIs and not about RDF
serialization.',
I have to admit that I'm slightly confused. In Cool URIs you are
referring to a certain
setup ('deployment scenarios in which the RDF data and the HTML data is
served separately').
Also the figure right before section 3.1 suggests that there is an
explicit RDF document
and an HTML document, each with a distinct URL. As you know, this is not
the case with RDFa.

So, that is were my confusion stems from. I know that due to time
constraints you decided
that this is the way it is. It would still be nice to learn why the
figure right before section 3.1 
(sorry, no label available) 'shows the desired relationships between a
resource and its describing documents'.

Cheers,
	Michael

[1] http://lists.w3.org/Archives/Public/semantic-web/2007Dec/0121.html

----------------------------------------------------------
 Michael Hausenblas, MSc.
 Institute of Information Systems & Information Management
 JOANNEUM RESEARCH Forschungsgesellschaft mbH
  
 http://www.joanneum.at/iis/
----------------------------------------------------------
 

>-----Original Message-----
>From: Leo Sauermann [mailto:sauermann@dfki.uni-kl.de] 
>Sent: Thursday, December 20, 2007 12:36 PM
>To: Hausenblas, Michael
>Cc: semantic-web@w3.org; Leo Sauermann
>Subject: Re: Cool URIs, the Semantic Web and Everything
>
>Hausenblas, Michael schrieb: 
>
>	Leo,
>	
>	Thanks for your explanation. I remain not totally convinced :)
>	  
>
>good, then give a practical example (using concrete RDFa code) 
>where you think some work needs to be done and provide a 
>suggestion how to solve it. That you are not convinced may be 
>caused by various reasons we don't know about, shine light on them.
>
>
>
>	
>	So, *if* we agree on what you said, IMHO we should 
>	reconsider the following paragraph in 'Cool URIs' [1]:
>	
>	'The solutions described in the following apply to 
>deployment scenarios 
>	in which the RDF data and the HTML data is served 
>separately, such as a
>	standalone RDF/XML document
>	along with an HTML document. The metadata can also be 
>embedded in HTML,
>	using technologies such as
>	RDFa [RDFa Primer], microformats and other documents to 
>which the GRDDL
>	[GRDDL] mechanisms can be applied. 
>	In those cases the RDF data is extracted from the returned HTML
>	document.'
>	  
>
>I see no reason for changes until you exactly specify where 
>this paragraph contradicts http-range-14 or other TAG 
>resolutions or W3C recommendations.
>
>the point is that RDF/XML, N3, RDFa and GRDDL are mimetypes 
>encoding RDF triples while URIs are something used inside 
>these RDF triples, so at the beginning both are completly 
>different and do not affect each other.
>
>"Cool uris" is about URIs and not about RDF serialization. 
>
>best
>Leo
>
>
>
>	
>	Still unsure if this is just the tip of the iceberg ...
>	  
>
>	
>	Cheers,
>		Michael
>	
>	[1] http://www.w3.org/TR/2007/WD-cooluris-20071217/#solutions
>	
>	----------------------------------------------------------
>	 Michael Hausenblas, MSc.
>	 Institute of Information Systems & Information Management
>	 JOANNEUM RESEARCH Forschungsgesellschaft mbH
>	  
>	 http://www.joanneum.at/iis/
>	----------------------------------------------------------
>	 
>	
>	  
>
>		-----Original Message-----
>		From: Leo Sauermann [mailto:sauermann@dfki.uni-kl.de] 
>		Sent: Thursday, December 20, 2007 3:43 AM
>		To: Hausenblas, Michael
>		Cc: semantic-web@w3.org; Leo Sauermann
>		Subject: Re: Cool URIs, the Semantic Web and Everything
>		
>		Hi Michael, RDFa people,
>		
>		The question is if httpRange-14 [2] is valid in 
>the case of XHTML+RDFa.
>		
>		The answer is that httpRange-14 is to 
>distinguish URIs for information 
>		resources ("web documents") from real-world 
>objects (the person 
>		"Alice"). As such, it is a recommendation on URIs.
>		
>		RDFa is an encoding of RDF, and typically an 
>RDFa document has two 
>		relations to URIs:
>		a) the URI of the RDFa document (=the 
>information resource where I can 
>		download the RDFa document)
>		b) the URIs used as subjects, predicates, 
>objects inside RDF 
>		statements 
>		written inside RDFa documents
>		
>		a) is usually a http-200 uri, and a) is an 
>information resource (= a 
>		document).
>		In the rdf statemetns written inside  A, you 
>would use both URIs for 
>		real-world objects and information resources.
>		example (I don't know  rdfa syntax by heart 
>now, assume this is rdfa):
>		
>		document at www.example.com/homepage/aboutAlice
>		<html>
>		<p 
>rdf:about="http://www.example.com/identifiers/alice#this" 
><http://www.example.com/identifiers/alice#this> >
>		 rdf:type foaf:Person.
>		</p>
>		<p 
>rdf:about="http://www.example.com/moreidentifiersusing303/bob" 
><http://www.example.com/moreidentifiersusing303/bob> >
>		rdf:type foaf:Person
>		</p>
>		</html>
>		
>		assuming this would be valid RDFa, the URI 
>.../aboutAlice is a 
>		http-return-200 informaiton resource
>		.../alice#this is a real-world object as it is 
>not a document (as I 
>		understand timbl on that)
>		...303/bob is not intuitively distinguishable - 
>if you ignore the 
>		rdf:type relation you don't know what it is. So 
>for this uri you do a 
>		HTTP get and the server would return a 303 
>redirect as described in 
>		"cool uris".
>		once oyu did the 303, you knowthat ....303/bob 
>is a real world object.
>		
>		so RDFa and 303'/httprange14 are 
>recommendations caring about 
>		different 
>		angles, 303 is only concerned about URIs, RDFa 
>about an RDF 
>		serialization. Technically they don't interfere.
>		
>		If I would use RDFa much and would like cool 
>uris, I would go for 
>		#-uris, they are simple to use and easy to 
>embed in RDFa.
>		but as shown above, you can use any URI you 
>want inside rdfa.
>		
>		best
>		Leo
>		
>		
>		Hausenblas, Michael schrieb:
>		    
>
>			===
>			Disclaimer: Michael, with his 
>RDFa-Task-Force-member hat off ;)
>			===
>			
>			As I gathered "Cool URIs for the 
>Semantic Web" is a Working 
>			      
>
>		Draft, now.
>		    
>
>			Congrats to Leo and his team, great job! 
>			
>			The following might sound like a naive 
>question - and I might 
>			have missed something :) - but: Is TAG 
>finding httpRange-14 [2] 
>			equally valid in the case of XHTML+RDFa?
>			
>			I've put together some initial thoughts 
>at the ESWiki [3]
>			- any comments welcome!
>			
>			Cheers,
>				Michael
>			
>			[1] 
>			      
>
>		
>http://lists.w3.org/Archives/Public/public-swd-wg/2007Dec/0103.html
>		    
>
>			[2] 
>http://www.w3.org/2001/tag/issues.html#httpRange-14
>			[3] http://esw.w3.org/topic/RDFa_vs_RDFXML
>			
>			
>----------------------------------------------------------
>			 Michael Hausenblas, MSc.
>			 Institute of Information Systems & 
>Information Management
>			 JOANNEUM RESEARCH Forschungsgesellschaft mbH
>			 Steyrergasse 17, A-8010 Graz, AUSTRIA
>			
>			 <office>
>			    phone: +43-316-876-1193 (fax:-1191)   
>			   e-mail: michael.hausenblas@joanneum.at
>			      web: http://www.joanneum.at/iis/ 
>			
>			 <private>
>			   mobile: +43-660-7621761
>			      web: http://www.sw-app.org/ 
>			
>----------------------------------------------------------
>			
>			  
>			      
>
>		
>		    
>
>	
>	  
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Received on Friday, 21 December 2007 08:24:44 GMT

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