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Re: Contd: [pedantic-web] question about sioc / foaf usage

From: Nathan <nathan@webr3.org>
Date: Tue, 01 Dec 2009 17:38:18 +0000
Message-ID: <4B15548A.6050709@webr3.org>
To: Kingsley Idehen <kidehen@openlinksw.com>
CC: Linked Data community <public-lod@w3.org>, pedantic-web@googlegroups.com, SIOC-Dev <sioc-dev@googlegroups.com>
Hi All,

To follow on a conversation I'm having with Kingsley at the minute, and
to make it public, I'm also cc'ing in public-lod, pedantic-web and the
sioc user list, as it is to do with all 3. Please do give feedback and
correct me where I'm wrong. Especially if you can inline comment where
something is wrong in my understanding.

Kingsley Idehen wrote:
> Nathan wrote:
>> so do / should the Post, HTML Document and RDF Document all have
>> different Identifiers?
> If you want to make a statement (create a record) describing anything
> you need an Identifier for the subject of your description. If you want
> said description (a graph pictorial) to be fully explorable using HTTP
> (what Linked Data is about) then you shouldn't use the URL (Address of a
> Resource) as its Identifier. An HTTP GET against a URL has specific
> consequences distinct from an HTTP GET against a Generic HTTP scheme URI
> (a genuine Identifier/Name that Identifies an Object/Resource/Data
> Item/Entity).
> 
> Rather than do the whole 303 and hash URI dance (counter productive
> since it dances around the issue of Data Identity), see if this document
> of Data Object Identity clarifies things for you re. Identifiers.
> 
> Links:
> 
> 1.
> http://www.cs.cmu.edu/afs/cs.cmu.edu/user/clamen/OODBMS/Manifesto/htManifesto/node4.html
> 

okay.. here's the set-up; I have:

* a "Post" which is a <sioc:Post>
* a HTML Document which contains (among other things) a human readable
representation of the <sioc:Post> at an URL
* a RDF Document which contains a graph pictorial of the <sioc:Post>
which is published at an URL

to describe or reference the <sioc:Post> I have to give it a URI:
  <http://example.lod/uri/post-123>

to describe or reference the HTML Document I have to give it a URI:
  <http://example.lod/uri/html-document-123>
in addition the HTML document has an URL
  <http://example.lod/documents/html-document-123.html>

to describe or reference the RDF Document I have to give it a URI:
  <http://example.lod/uri/rdf-graph-123>
in addition the RDF document has an URL
  <http://example.lod/documents/rdf-document-123.rdf>


now, I'm assuming the RDF Document will need to be self describing (also
contain a graph pictorial about itself, as well as the <sioc:Post> -
here's a very simplified version of the triples it'd contain.

  <http://example.lod/uri/rdf-graph-123> <rdf:type> <foaf:Document> ;
	<dc:title> "SIOC Post profile for post-123"@en
	<foaf:primaryTopic> <http://example.lod/uri/post-123> .

  <http://example.lod/uri/post-123> <rdf:type> <sioc:Post> .

Q1: is <foaf:primaryTopic> correct here?

to say that the <sioc:Post> is contained by this graph we'd add the triple:
  <http://example.lod/uri/post-123>
	<sioc:link> <http://example.lod/uri/rdf-graph-123> .

then we need to say where the rdf graph can be found (provide it's URL):
  <http://example.lod/uri/rdf-graph-123>
	<??????> <http://example.lod/documents/rdf-document-123.rdf> .

Q2: which ontology does one use for <??????> in the above triple?

then we need to say that the HTML document is a document, that contains
a human readable version of the <sioc:Post> (amongst other things)

  <http://example.lod/uri/html-document-123>
	<rdf:type> <foaf:Document> ;
	<foaf:primaryTopic> <http://example.lod/uri/post-123> .

Q3: is the HTML Document a <sioc:Container>, which is a container of the
<sioc:Post>?
    <http://example.lod/uri/html-document-123>
	<rdf:type> <foaf:Document> , <sioc:Container> ;
	<foaf:primaryTopic> <http://example.lod/uri/post-123> ;
	<sioc:container_of> <http://example.lod/uri/post-123> .

Q4: should we also say the description of the HTML Document is also
contained by this graph?
  <http://example.lod/uri/post-123>
	<sioc:link> <http://example.lod/uri/rdf-graph-123> .

Q5: how do we specify the URL of the HTML Document?
    <http://example.lod/uri/html-document-123>
	<?????> <http://example.lod/documents/html-document-123.html> .

I think that's enough for now; all feedback welcome!

regards

nathan
Received on Tuesday, 1 December 2009 17:39:15 UTC

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