Re: Semantic Web Languages

On 31 Mar 2006, at 23:58, John F. Sowa wrote:
> Danny,
>
> I don't violently disagree with anything you said, but I
> do have some quibbles and a couple of extra points:
>
> > One of my dayjob contracts requires a kind of validation
> > outside of RDF/OWL, this I'm implementing using custom
> > (mostly hard-coded) logic on top of the RDF/OWL representation.
> > ... Throughout this work I'm mixing and matching numerous
> > RDFS vocabularies/OWL ontologies as demanded by the domain.
>
> I realize that many people have been doing useful work with RDF
> and OWL, and since nothing better is widely available, people
> have to live with what they've been given.  But I believe that
> anything that has been done with RDF could have been done sooner,
> better, and with much greater efficiency with an XML tag that
> says LANG=TupleList followed by an enclosed list of tuples in
> the form (and with the option of n-ary tuples as well):
>
>    (R1 a b) (R2 c d) (R3 e f) (R4 g h) ...

There have been numerous xml proposals along this line. Tim Bray  
proposed one.
TriX is another [1]. But you could also look at NTriples [3] for a  
very simple non xml version.

> I agree that taste is hard to quantify, but when the designer
> of a language apologizes for his mistakes, that should be a
> serious warning sign:
>
>    http://www.tbray.org/ongoing/When/200x/2003/05/21/RDFNet

You keep mistaking syntax and semantics!

The xml serialisation of rdf is just one serialisation. Xml/rdf is in  
fact very interesting, but is limited by the attempt to create a data  
exchange language with what is in effect a mark up language. Please  
learn some other language such as Turtle. If you don't like it, you  
can come up with a better one.

> For a more recent interview with Tim Bray (2005), see
>
> http://www.acmqueue.com/modules.php? 
> name=Content&pa=printer_friendly&pid=282&page=3
>
> For a set of slides, by Mark Butler (which were endorsed by Tim B.),
> see
>
>    http://www.hpl.hp.com/personal/marbut/isTheSemanticWebHype.pdf

Tim Bray was involved with the xml serialisation of RDF. That did not  
produce as good a solution as was hoped. But that is in fact not a  
real problem.

One quote though stands out
[[
TB I got involved in the work that produced RDF, but I found RDF to  
be a really hard sell. That quickly became mixed up with a whole  
bunch of classic KR (knowledge representation) people who wanted to  
go refight the AI wars of the ’80s. And I just didn’t care.
]]

And frankly I understand him.

> In a preface to those slides, Mark said that SPARQL combined
> with RDF has proved to be more successful than Xpath with just
> XML.  However, the same could have been said about SPARQL (or
> even plain SQL) combined with tuple lists with the syntax above
> -- and probably with a major improvement in both space and time.

Why always get cought up on syntax?

>
> > The layering of the framework allows me to do all this in a
> > Web-friendly, consistent fashion. If this isn't modular, I
> > don't know what is.
>
> But you can get just as much web friendliness and just as much
> or more modularity with XML tags that say LANG=xxx.  As Unix has
> demonstrated, it is possible to have an extremely modular system
> that supports any kind of language or any kind of GUI anyone might
> want -- without enforcing any constraints on syntax.

exactly. RDF enforces no constraint on syntax. If you want you could  
even rework prolog to map it to rdf.
I have done so with Java [4] of all languages. You could even use  
first order logic. In first order logic names and predicates work  
exactly as they do in RDF. Names are meant to be universally unique.  
It is just that logicians had not invented URLs, and they prefer very  
terse syntax so they write R(a,b). The problem is that there is no  
way for one mathematician's R to relate easily to another  
mathematicians. The SemWeb uses URLS for that. And that works very well.


Henry Story

>
> John

[1] http://www.hpl.hp.com/techreports/2004/HPL-2004-56.pdf
[2] http://bblfish.net/blog/page9.html#2005/09/05/01-25-45-493
[3] http://www.w3.org/2001/sw/RDFCore/ntriples/
[4] http://blogs.sun.com/roller/page/bblfish? 
entry=java_annotations_the_semantic_web

Received on Sunday, 2 April 2006 06:49:39 UTC