W3C home > Mailing lists > Public > semantic-web@w3.org > December 2007

Re: Cool URIs, the Semantic Web and Everything

From: Leo Sauermann <sauermann@dfki.uni-kl.de>
Date: Thu, 20 Dec 2007 11:36:04 +0000
Message-ID: <476A53A4.9000401@dfki.uni-kl.de>
To: "Hausenblas, Michael" <michael.hausenblas@joanneum.at>
CC: semantic-web@w3.org, Leo Sauermann <leo.sauermann@dfki.de>
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">
>>  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 Wednesday, 26 December 2007 00:31:17 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 21:45:19 GMT