W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > February 2002

Re: why not take just the 2 ???

From: <jos.deroo.jd@belgium.agfa.com>
Date: Sun, 3 Feb 2002 14:22:37 +0100
To: patrick.stickler@nokia.com
Cc: w3c-rdfcore-wg@w3.org
Message-Id: <OF95F9FB7F.F2023A08-ONC1256B55.0049365C@bayer-ag.com>
[I'm scraping this from the archive, because mail isn't coming through]

> > ??? why not take just the 2
> >
> > dt-local = S-A + TDL-local
> >
> > :Jenny :age [ xsd:int.map "30"; rdf:dtype xsd:int.val ] .
> >
> > dt-global = S-B
> >
> > :Jenny :age "30" .
> > :age rdfs:range xsd:int.lex .
> >
> > --
> > Jos De Roo
> >
> >
> Firstly, the above is not TDL-local. TDL-local
> uses rdf:value to bind the literal (lexical form)
> to the bnode and the value of rdf:type or rdf:dtype
> is the URI of the datatype, not the value space.

I know, but is was some kind of fusion
(although I often seem to cause confusion)

> Secondly, the above approach doesn't really do
> anything more than TDL-local and TDL-global

which is ok, no?

> except require that we have 4 URIs for each
> datatype rather than one and preclude use of
> both idioms together (see next)

well I just see 3 URIs, but I agree that is more
than 1 URI

> Thirdly, having the range of a literal node as
> *.lex and the range of a bnode *.val is precisely
> the problem that S has with cohabitation of its
> local and global idioms. One cannot then define
> a range for the local idiom intended to express
> a constraint without conflict of interpretation
> (is the bnode *.lex or *.val?)

well, one can with the axiom [*]
  { ?s ?p ?o . ?p rdfs:range xsd:int,lex } ->
    { ?s ?p [ xsd:int,map ?o; rdf:dtype xsd:int,val ] }

> There is already alot of negative opinion about
> how the RDF datatyping proposals are referencing
> XML Schema datatype URIs. I suspect that any
> solution that uses anything other than the pre-
> defined (or user defined) single URIs for each
> datatype will not be acceptable.

but this is meant for machines, no?

> The TDL approach of having the datatype URI denote
> the entire datatype, not just one of its components,
> seems to sync the closest with the desires of the
> XML Schema and "don't graze on other's grass" folks.

well, it's coexistence I think

> I think one key difference between the TDL and
> S "philosophies" is that S wants/needs to use a
> unique URI for each component of a datatype
> in order to make the significance of those components
> explicit in the representation, whereas TDL uses the
> single URI of a datatype to define a context within
> which the MT provides a consistent interpretation for
> the lexical form (literal).

if you (in TDL-global) only have the fact :Jenny :age "30"
and *no* range information for :age then you have *no*
interpretation for "30"

> I concede (as I always have) that having an MT
> that works and meets folks expectations/needs is
> imperative -- but much of our discussion seems to
> be focusing solely on the state of the MT and
> does not sufficiently consider usability, efficiency
> of expresssion, and in short, what the ramifications
> will be for "common users".

thanks ;-)

> Multiple URIs, synonymous idiom-specific vocabularies,
> etc. etc. may make the MT easier to write, but it
> makes life in general much harder for the user, and
> after all, at the end of the day, if RDF datatyping
> is percieved to be too complicated, regardless of
> how beautiful and correct the MT is, folks won't use
> it. Eh?

I don't think it makes life for machines any harder

> The S approach makes things easier for writing the
> MT but harder for the users. Who should we be trying
> most to make things easiest for? I think the users.
> Please let us ask ourselves, not simply does it work,
> but does it make life easier for the majority of folks
> who want to use RDF for common metadata and knowledge
> management tasks. And the majority of folks are not
> necessarily those building complex KR or expert
> systems to explore theorem proving, etc. but folks
> who simply want to describe things and find things
> based on those descriptions.

thanks again ;;--))

> RDF is already percieved as difficult and confusing
> enough -- we don't need to add to that perception by
> having a cumbersome datatyping solution (if we can
> by any reasonable means avoid it).
> I think we should perhaps add an item to the desiderada,
> that the solution be as simple and easy to use as
> possible, even at the expense of a more complicated
> MT.

well, I wouldn't know...


[*] I use int,lex instead of int.lex to be able to test stuff
Received on Sunday, 3 February 2002 08:28:27 UTC

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