A modest note on rdf:text from the an OWLer

I've been following along on the conversation and not contributing, but
I'm now going to stick by toe in.   


Here is a fictious dialog between several points of view.  You may
decide, if you wish, to assign human actors to these points of view.
That is completely up to you, I'm not saying that anyone holds these
views as I've stated them.

(An well-known Zakim meeting and IRC chat room.)

IH:  We need better datatype support in OWL 2!  
IH:  But how can it be done?
BM:  Let's use XML Schema datatypes and facets!
IH:  Sounds good, go for it.
JC:  But what about plain literals?  We need to support all RDF graphs!
BM:  Hmm, we need a datatype for them.  I know, we'll just use
     xsd:string - its extension includes all reasonable plain literals. 
JC:  Not so - to satisfy internationalization concerns we need to also
     handle plain literals with a language tag.
BM:  Then let's have a new datatype, owl:text, that includes both
     strings without a language tag and strings with a language tag.  It
     is just like xsd:string but with complete coverage of all plain
     literals. It is a perfectly good RDF datatype, conforms perfectly
     to XML Schema Datatypes, there are no downsides.
JC:  Sounds like a plan.  I'm happy.

(Lots of on-stage document hacking.)

(AP enters, announced by Zakim.)

AP:  What's this owl:text?  This other WG is doing the same thing and so
     both WGs should use the same name for it!
IH:  Hmm.  OK, let's form a task force and come up with a joint
     document.
BM:  Let's call the datatype rdf:text, because that is a good
     description of the purpose of the joint datatype.
JC:  OK by me, but not really necessary, any name will do.
AP:  That's fine.  This other WG just needs to add functions, which you
     in OWL don't seem to have.
BM:  I don't see any reason not to include a section on functions for
     rdf:text. 
JC:  OK by me, but it doesn't make me any happier.  I don't need the
     functions. 
IH:  Let's include a bit of wording to encourage tools to use plain
     literals whereever possible, just so that tools that are not 
     aware of the rdf:text datatype work as if they did.
BM:  Why just for rdf:text?  Other datatypes have the same issue, or
     even worse!  We are not going to require normalization of all
     literals!  Making bad design choices just to support existing 
     tools is not a good idea in general, and is certainly not a good
     idea here.  
IH:  I know, I know, but making a special case for rdf:text might make
     it more acceptable.
BM:  OK, but you are going to be sorry you ever tried to be nice.

(A moderate amount of on-stage document hacking.)

IH:  Hello world!  The OWL WG and this other WG have this great new
     thing for you!  A new datatype, called rdf:text, for any sort of
     internationalized text. 
(Tomatoes being thrown from everywhere in the audience.)
IH:  Did I say "any sort of internationalized text"?  I meant to say
     "strings with language tags".
(More tomatoes being thrown, but only from one place in the audience.)
IH:  Oh, you don't like rdf:text at all?  Well, the OWL WG will just go
     back to the previous happy situation and have a new datatype in
     OWL, called owl:text, to go along with our use of lots of new XML
     Schema datatypes and datatype facets.  Other WGs can use this new
     datatype if they want, or not.  Other WGs can even define functions
     on this new datatype, the OWL WG has nothing to say about this.
IH:  [Aside to BM]  I'm really, really sorry.
BM:  [Aside to IH]  I told you so.

(A bit of on-stage document hacking.)

IH:  Hello world!  The OWL WG is proud to present its CR documents!
     Sorry about the previous brouhaha.
AP:  [Inaudible] Grumble, grumble.

(Everyone realizes that if they throw tomatoes at owl:text they have to
also shoot down the entire idea of RDF datatypes and D-entailment.)

(World peace reigns!)


This appears to be the result that is being argued for.


Peter F. Patel-Schneider
Bell Labs Research

Received on Thursday, 21 May 2009 01:01:23 UTC