W3C home > Mailing lists > Public > public-lod@w3.org > June 2010

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

From: Nathan <nathan@webr3.org>
Date: Wed, 30 Jun 2010 21:47:05 +0100
Message-ID: <4C2BAD49.8060502@webr3.org>
To: Kingsley Idehen <kidehen@openlinksw.com>
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>
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 ) ?

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.

Best,

Nathan

please do correct me if I'm wrong
Received on Wednesday, 30 June 2010 20:48:07 UTC

This archive was generated by hypermail 2.3.1 : Sunday, 31 March 2013 14:24:27 UTC