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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 16:54:39 -0400
Message-ID: <4C2BAF0F.20604@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:
> Kingsley Idehen wrote:
>> 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.
>
> Surely that's Linked Data or a variant of EAV, not RDF - why should 
> the core level data model be restricted so that it can't be used to 
> say simple things like { 1 x:lessThan 2 ) ?

Yes, that's the context of my response.

I (biases on my sleeve) believe that local RDF (as per the past) has 
limited value.

>
> Moreover, { :a :b "something" } == { "something" [owl:inverseOf :b] :a }
>
> aside: you know I fully grok all the benefits of linked data and am a 
> huge proponent, but rdf at it's core isn't linked data and saying:
>   { x:London rdfs:label "London" }
> is the same as saying
>   { "London" is rdfs:label of x:London }
> afaik, directionality doesn't come in to it.

Yes, RDF != Linked Data. But ironically, it might take this entire 
debate to fix that perception bug :-)

>
> Best,
>
> Nathan
>
> please do correct me if I'm wrong
>


-- 

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 20:55:18 UTC

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