Re: Literals (Re: model theory for RDF/S)

> I don't see anything wrong with how DAML encorporates
> XML Schema data types. It may be, though, that such data
> type mechanisms should live at a lower level, namely RDFS
> -- or maybe not. I'm undecided about that.
>
> They don't, though, belong IMO at the RDF level, in the
> graph.

Wow, I agree with you! There was some discussion that when a datatyped
literal is added to an internal RDF store, it should be given an ID so that
the application can keep track of its type-ness. In other words, when you
have:-

   "xyz" a :X .
   "xyz" a :Y .

you should add IDs to the literals internally to keep a track of them... so
that they are noted as being different. But that's rubbish, because they're
noted as being different in the model, and the model is preserved in the
application. If the model loses the information about the typing, it does
not need to retain the ID information, because it no longer believes the
strings to be typed as anything more specific that simply rdfs:Literal.

Bigger problems that face designers of internal RDF stores include how to
do asserted reified statements, and fiddling about with contexts.

But, I still disagree with generating a new URI scheme for datatypes. There
is no real difference between:-

   "xyz" rdf:type :abc .

and:-

   <lit:abc:xyz> a rdfs:Resource .

Except that the former is decentralized and keeps more inline with the
whole principle of the Semantic Web, which is decentralization. It wouldn't
be so bad to have a range of very, very, important literals in a "lit:" URI
space (they could then be used by non-RDF systems), but you certainly can't
have a centralized URI scheme for every datatype ever; it's pointless (and
most likely, you're not suggesting that).

Cheers,

--
Kindest Regards,
Sean B. Palmer
@prefix : <http://webns.net/roughterms/> .
:Sean :hasHomepage <http://purl.org/net/sbp/> .

Received on Wednesday, 3 October 2001 13:25:29 UTC