- From: Kingsley Idehen <kidehen@openlinksw.com>
- Date: Sun, 08 Jul 2007 13:44:48 -0400
- 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 UTC