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Re: Subjects as Literals, [was Re: The Ordered List Ontology]

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Wed, 30 Jun 2010 14:30:25 -0400
Message-ID: <4C2B8D41.60309@openlinksw.com>
To: nathan@webr3.org
CC: Pat Hayes <phayes@ihmc.us>, Toby Inkster <tai@g5n.co.uk>, Dan Brickley <danbri@danbri.org>, Linked Data community <public-lod@w3.org>, Semantic Web <semantic-web@w3.org>
Nathan wrote:
> Pat Hayes wrote:
>> On Jun 30, 2010, at 6:45 AM, Toby Inkster wrote:
>>> On Wed, 30 Jun 2010 10:54:20 +0100
>>> Dan Brickley <danbri@danbri.org> wrote:
>>>> That said, i'm sure sameAs and differentIndividual (or however it is
>>>> called) claims could probably make a mess, if added or removed...
>>>
>>> You can create some pretty awesome messes even without OWL:
>>>
>>>     # An rdf:List that loops around...
>>>
>>>     <#mylist> a rdf:List ;
>>>         rdf:first <#Alice> ;
>>>         rdf:next <#mylist> .
>>>
>>>     # A looping, branching mess...
>>>
>>>     <#anotherlist> a rdf:List ;
>>>         rdf:first <#anotherlist> ;
>>>         rdf:next <#anotherlist> .
>>>
>>
>> They might be messy, but they are *possible* structures using 
>> pointers, which is what the RDF vocabulary describes.  Its just about 
>> impossible to guarantee that messes can't happen when all you are 
>> doing is describing structures in an open-world setting. But I think 
>> the cure is to stop thinking that possible-messes are a problem to be 
>> solved. So, there is dung in the road. Walk round it.
>>
>
> Could we also apply that to the 'subjects as literals' general 
> discussion that's going on then?
>
> For example I've heard people saying that it encourages bad 'linked 
> data' practise by using examples like { 'London' a x:Place } - whereas 
> I'd immediately counter with { x:London a 'Place' }.
>
> Surely all of the subjects as literals arguments can be countered with 
> 'walk round it', and further good practise could be aided by a few 
> simple notes on best practise for linked data etc.

IMHO an emphatic NO.

RDF is about constructing structured descriptions where "Subjects" have 
Identifiers in the form of Name References (which may or many resolve to 
Structured Representations of Referents carried or borne by Descriptor 
Docs/Resources). An "Identifier" != Literal.

If you are in a situation where you can't or don't want to mint an HTTP 
based Name, simply use a URN, it does the job.


>
> Best,
>
> Nathan
>
>


-- 

Regards,

Kingsley Idehen	      
President & CEO 
OpenLink Software     
Web: http://www.openlinksw.com
Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca: kidehen 
Received on Wednesday, 30 June 2010 18:31:19 UTC

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