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Re: Why do we name nodes and not edges?

From: Hugh Glaser <hg@ecs.soton.ac.uk>
Date: Fri, 27 Jul 2012 16:33:20 +0000
To: Michael F Uschold <uschold@gmail.com>
CC: Hugh Glaser <hg@ecs.soton.ac.uk>, Steve Harris <steve.harris@garlik.com>, Austin William Wright <aaa@bzfx.net>, Melvin Carvalho <melvincarvalho@gmail.com>, Semantic Web <semantic-web@w3.org>
Message-ID: <46FF0A80-614F-4390-8CFB-87D63E314508@soton.ac.uk>
I don't disagree.
I am not sure that avoiding reification doesn't fall into the class of things that make it more complex.
Too many double negatives - twice.
To put it another way: It might be that reification is one of the things that would make things easier.
Easier as a user, I mean, not necessarily for the "toilers".
Users always find it strange that the R word seems to be the last taboo - it seems perfectly natural to be able to name triples, especially as we tell them that URIs are there to name things, and you can name anything.

On 27 Jul 2012, at 17:25, Michael F Uschold <uschold@gmail.com>
 wrote:

> Sure, reification is a bit of a pain sometimes if you have lots of nary relations in your application domain.
> 
> But who is is a problem for? So it makes specifying raw queries a bit more painful - agreed.  However end users need not know or care about it.  It can be buried behind query interfaces and other things for end users.  
> 
> Michael 
> 
> On Fri, Jul 27, 2012 at 4:47 AM, Hugh Glaser <hg@ecs.soton.ac.uk> wrote:
> 
> On 27 Jul 2012, at 09:37, Steve Harris <steve.harris@garlik.com> wrote:
> 
> > Yeah, but that example uses reification, which is at best frowned upon.
> >
> > Increasingly my reaction to these kinds of questions is: maybe you shouldn't be using RDF.
> >
> > RDF has limits of expressivity, [all IMHO] it's best for describing things in a way that the descriptions can easily be consumed by other reasonably generic processors - once you start delving off into obscure corners - e.g. something that was said by person X, believed by person Y, but not person Z, and then published by W - then you're no longer in the territory of easily. Even once you've somehow parsed that lot, doing anything useful with it - in an even vaguely generic way - is beyond complex.
> I like this description.
> I like using SemWeb technologies for the things that they are good at, which in my brain means it has to be easy.
> People are welcome to think hard about how to push back the frontiers of what they might achieve, of course - that is research.
> I think the platform that others have toiled over in the last decade has provided us with something that can be easily used with confidence.
> But if some area is getting complex, than maybe it isn't the right technology.
> Which of course means it could benefit from more toil, of course, such as provenance is doing.
> Me? Clearly I'm just a parasite for others' toil.
> >
> > - Steve
> >
> > On 2012-07-26, at 16:30, Austin William Wright wrote:
> >
> >> At least in RDF, resources (the node of the graph) are first class citizens.. You can describe edges as resources, you just need give the resource an identifier first:
> >>
> >> <triple1234>
> >>     a rdf:Statement ;
> >>     rdf:subject <foo> ;
> >>     rdf:predicate <http://example.com/edge/123456> ;
> >>     rdf:object 1 .
> >>
> >> Since edges/RDF statements with the same subject, predicate, and object must be the same edge, this identifies edges. Any rdf:Statement resources with the same values for subject, predicate, object, would be different URIs for the same resource.
> >>
> >> We don't see this more often because usually edges aren't resources "of significance", there's not much reason to describe specific facts. Generally, people make statements on entire graphs of RDF statements, the graph getting a URI. These don't usually get stored themselves as RDF statements for practical database reasons, but you could, as an RDF Collection of rdf:Statement resources.
> >>
> >> Austin Wright.
> >>
> >> On Wed, Jul 25, 2012 at 8:07 AM, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
> >> Sorry if this topic has been covered before, but I have a question based on the axioms of the web, in particular:
> >>
> >> Axiom 0a: Universality 2    Any resource of significance should be given a URI.
> >>
> >> In this case we consider the web to be a directed graph (of nodes and edges), where a node corresponds to a resource but edge does not.
> >>
> >> We are encouraged to make nodes universal by giving them a URI.
> >>
> >> Why dont edges get the same treatment, ie encouragment to give it a (universal) name.  Is it even practical?
> >>
> >> I know there's such thing as reification but that seems to be unpopular (maybe before my time).
> >>
> >> I'm just curious as to whether this seems asymmetrical, that nodes are seemigly treated in one way, and edges in another?
> >>
> >
> > --
> > Steve Harris, CTO
> > Garlik, a part of Experian
> > +44 7854 417 874  http://www.garlik.com/
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> >
> 
> 
> 
> 
> 
> -- 
> Michael Uschold, PhD
>    Senior Ontology Consultant, Semantic Arts
>    http://www.semanticarts.com
>    LinkedIn: http://tr.im/limfu
>    Skype, Twitter: UscholdM
> 
> 
> 
> 
Received on Friday, 27 July 2012 16:39:05 UTC

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