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Re: Cool URIs, the Semantic Web and Everything

From: Richard Cyganiak <richard@cyganiak.de>
Date: Thu, 20 Dec 2007 11:02:23 +0000
Cc: "Leo Sauermann" <sauermann@dfki.uni-kl.de>, <semantic-web@w3.org>, "Leo Sauermann" <leo.sauermann@dfki.de>
Message-Id: <B7AD1CE4-FACA-4AA0-88EC-B8ADD90D28A1@cyganiak.de>
To: "Hausenblas, Michael" <michael.hausenblas@joanneum.at>

Michael,

On 20 Dec 2007, at 07:45, Hausenblas, Michael wrote:
> Thanks for your explanation. I remain not totally convinced :)
>
> So, *if* we agree on what you said, IMHO we should
> reconsider the following paragraph in 'Cool URIs' [1]:

Okay, so you object to the paragraph quoted below. Perhaps I'm failing  
to read between the lines, but I don't know *what* your objection is.  
An explanation that refers to the text of the paragraph would be much  
appreciated.

Cheers,
Richard


> '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.'
>
> 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">
>> rdf:type foaf:Person.
>> </p>
>> <p rdf:about="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/
>>> ----------------------------------------------------------
>>>
>>>
>>
>>
>
>
Received on Thursday, 20 December 2007 11:02:35 GMT

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