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Re: Requirements for a possible "RDF 2.0"

From: Jiří Procházka <ojirio@gmail.com>
Date: Mon, 18 Jan 2010 23:55:38 +0100
Message-ID: <4B54E6EA.6060701@gmail.com>
To: Kjetil Kjernsmo <kjetil@kjernsmo.net>
CC: Pat Hayes <phayes@ihmc.us>, semantic-web@w3.org
This is what I wish never was introduced to RDF.
I was told literal datatypes are there for for some semantic reason I
don't understand, but why we there are language tags is completely
beyond me.

Thanks to this bad precedent we could introduce a special semantics for
measures (like you wish), time handling, events, grouping, and so on and
so on into the core RDF spec.

I hope you realize how wrong this is - no clear line drawn to decide
what should be in the core and what not. That clear line is what I
personally would like to come out of the "RDF 2.0".

I have my opinion on it, which I am ready to elaborate and defend - make
"ground level RDF" which defines nothing more than triples and literals
(without datatypes and language tags. Maybe bnodes would have to be
there too because of semantics.) and build the rest on top of it (call
it modules, semantic extensions, whatever).

These extensions would translate to triples so for example "hello"@en
would translate to:
  "hello" rdf:type rdflang:LanguageTaggedLiteral ;
    rdflang:language rfc5646:en .
(I am for having all-resource-wide owl:sameAs (not only instances) in
RDF core, thus literals as subject too)

Plus the extension would define the necessary semantics, possibly using
a different extension for expressing the axioms (if OWL or SWRL or
whatever isn't up to the job already)

Advantage of this modularity is that the tool implementators don't have
to shoot at a moving target, supporting stability and ease of adoption.
One of the extensions could define terms for expressing availability of
the extensions in various tools (DOAP-style mixed with software
repositories).

Anyway this isn't stripping down of the RDF. The "ground level RDF" +
some basic stack of extensions (more or less what is RDF today) could be
called the RDF, so people don't go reinventing the wheel again, not
noticing the extensions.

Back to you Kjetil - taking human usability in consideration in RDF core
design is recipe for disaster - a flawed evaluation of its domain, not
pragmatism. This is what RDF syntaxes (ie serializations) are about.
I am working (slowly) on a serialization which introduces distributed
macro system, not unlike C preprocessor, for expanding simple
expressions into triples, so for example instead of:
  "hello" rdf:type rdflang:LanguageTaggedLiteral ;
    rdflang:language rfc5646:en .
you would write
  ll:["hello"en].
Not as easy as easy as "hello"@en, but flexible. Anyway, still in alpha
stage.

Best,
Jiri

On 01/18/2010 10:31 PM, Kjetil Kjernsmo wrote:
> On Monday 18. January 2010 17:59:26 Pat Hayes wrote:
>> But how else would you naturally express a property of anything in  
>> RDF, than by writing a triple? It sounds like you want to not be using  
>> RDF at all :-)
> 
> Oh, yes, I do! We already have precedent: datatypes and languages are 
> "properties" of literals, and I think units should be done in much the same 
> way, unless we find a way to do it in a more general way, that is also 
> simple enough in practice.
> 
> Best,
> 
> Kjetil


Received on Monday, 18 January 2010 22:56:24 UTC

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