W3C home > Mailing lists > Public > semantic-web@w3.org > August 2012

Re: Why do we name nodes and not edges?

From: Steve Harris <steve.harris@garlik.com>
Date: Wed, 1 Aug 2012 12:08:22 +0100
Cc: Pat Hayes <phayes@ihmc.us>, Austin William Wright <aaa@bzfx.net>, Melvin Carvalho <melvincarvalho@gmail.com>, Semantic Web <semantic-web@w3.org>
Message-Id: <03E9BB05-E8B8-4D37-8A2C-09F1FA943530@garlik.com>
To: nathan@webr3.org
On 2012-07-31, at 13:56, Nathan wrote:

> Steve Harris wrote:
>> On 2012-07-31, at 07:04, Pat Hayes wrote:
>>> On Jul 27, 2012, at 3:37 AM, Steve Harris wrote:
>>>> Yeah, but that example uses reification, which is at best frowned upon.
>>> Look. If you want to refer to, and describe in RDF, an RDF triple, then you will be using reification whether you call it that or not. Reification, in this context, *means* describing RDF triples in RDF. And RDF reification is not "frowned upon" as far as the specs are concerned, so if this is what you want to do, go ahead and use it. It is perfectly legal, conformant, RDF. 
>> It is, but RDF Reification is very definitely frowned upon - not everyone agrees, and I'm somewhat neutral on the subject myself.
>>>> 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.
>>> Its messy, but its not hard to write stuff like this in RDF, after inventing the appropriate URI vocabulary to do it all, of course. And as for doing anything useful with it, well yes that might well be a problem, but not because its written in RDF. This stuff is just hard to do anything useful with, period. 
>> Sure, I didn't mean to imply that RDF made it more difficult, but I imagined/hoped (maybe falsely) that there were system designed for modelling this kind of stuff that would make it easier. Maybe complex temporal stuff would have been a better example. You /can/ do it in RDF, but there are better systems.
> Like quoting in N3?

I was thinking of temporal logics, and similar approaches. Quoting in N3 is only of marginal benefit in that case. People have extended RDF to support temporal stuff, but then it's not really RDF anymore.

- Steve

Steve Harris, CTO
Garlik, a part of Experian
+44 7854 417 874  http://www.garlik.com/
Registered in England and Wales 653331 VAT # 887 1335 93
Registered office: Landmark House, Experian Way, Nottingham, Notts, NG80 1ZZ
Received on Wednesday, 1 August 2012 11:08:53 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 19:48:39 UTC