W3C home > Mailing lists > Public > www-tag@w3.org > July 2007

Re: Linked Data Page Example: [Linking-open-data] Terminology Question concerning Web Architecture and Linked Data

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Sun, 08 Jul 2007 13:44:48 -0400
Message-ID: <46912290.2090906@openlinksw.com>
CC: Linking Open Data <linking-open-data@simile.mit.edu>, www-tag@w3.org, semantic-web@w3.org

Kingsley Idehen wrote:
> Kingsley Idehen wrote:
>> Kingsley Idehen wrote:
>>>>  
>>> Depends on the characteristics of the property "owl:sameAs" as used 
>>> in Tim's "Universe of Discourse" (Data Space) and here is why:
>>>
>>> Yes, if in Tim's Data Space Definition he asserts that "owl:sameAs" 
>>> is an "owl:SymmetricProperty" then his usage is unambiguous, as this 
>>> should result in identical triples when you SPARQL against his Data 
>>> Space using either URI (assuming we are not modeling the Web as a 
>>> single Graph). Of course, this assumes the SPARQL processor has 
>>> inference capabilities. Otherwise, "rdfs:seeAlso" would be the 
>>> preferred property as this is unambiguous (i.e. the aforementioned 
>>> URIs will produce varied Triples without introducing confusion).
>> In retrospect, the statement above is *incorrect* since "owl:sameAs" 
>> means the URIs in the Domain and Range are to be treated as 
>> "Identical".  It's up to RDF Clients / Consumers (e.g. Browsers and 
>> SPARQL Processors) to ensure that identical Triples are dereferenced 
>> from said URIs. Thus, Tim's usage is unambiguous :-)
>>
>>
>>
> All,
>
> Missing from the above is a SPARQL example.
> Graph URI: http://www.w3.org/People/Berners-Lee/card#i
>
> Query1:
>
> select distinct ?s ?p ?o
> where {{<http://www.w3.org/People/Berners-Lee/card#i> ?p ?o }
>         union
>       {?s ?o <http://www.w3.org/People/Berners-Lee/card#i>}
>      }
>
> Query2:
>
> select distinct ?s ?p ?o
> where {{<http://dbpedia.org/resource/Tim_Berners-Lee> ?p ?o }
>         union
>       {?s ?o <http://dbpedia.org/resource/Tim_Berners-Lee>}
>      }
>
>
> If the SPARQL Processor supports inferencing then Queries 1 & 2 should 
> produce identical results (Triples) for the Graph URI: 
> http://www.w3.org/People/Berners-Lee/card#i
All,

Here are two Dynamic Linked Data pages that demonstrates client side 
smushing/meshing of data from TimBL's Data Space 
<http://www.w3.org/People/Berners-Lee/card#i > and DBpedia via Tim's use 
of "owl:sameAs" .

1. 
http://demo.openlinksw.com/DAV/home/demo/Public/Queries/DataWeb/TimBL_Personal_URI_Smushing_DBpedia_URI.isparql 
- Linked Data Page
2. 
http://demo.openlinksw.com/DAV/home/demo/Public/Queries/DataWeb/TimBL_Personal_URI_Smushing_DBpedia_URI.rq 
- SPARQL Query Definition
3. 
http://demo.openlinksw.com/DAV/home/demo/Public/Queries/DataWeb/TimBL_DBpedia_URI_Smushing_Personal_URI.isparql 
- Linked Data Page
4. 
http://demo.openlinksw.com/DAV/home/demo/Public/Queries/DataWeb/TimBL_DBpedia_URI_Smushing_Personal_URI.rq 
- SPARQL Query Definition


-- 


Regards,

Kingsley Idehen	      Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO 
OpenLink Software     Web: http://www.openlinksw.com
Received on Sunday, 8 July 2007 17:45:17 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Thursday, 26 April 2012 12:47:46 GMT