W3C home > Mailing lists > Public > www-rdf-comments@w3.org > January to March 2002

Re: RDF Issue rdfms-literalsubjects

From: Seth Russell <seth@robustai.net>
Date: Mon, 25 Feb 2002 11:07:27 -0800
Message-ID: <00b901c1be2f$aacebb60$657ba8c0@c1457248a.sttls1.wa.home.com>
To: "Pat Hayes" <phayes@ai.uwf.edu>
Cc: <www-rdf-comments@w3.org>
From: "Pat Hayes" <phayes@ai.uwf.edu>

> Some people want tidy literal nodes. Some people want to allow
> 'multiple' uses of literals.

I wonder who in their right mind would use the same literal in the *same
graph* to mean two different incompatible things.

>As long as literals are not subjects, we
> can kind of finesse this mismatch of expectations by making the same
> literal 'contribute' different meanings to each triple it happens to
> be in.  But if literals can be subjects (as well as objects) then
> this will break, for the reasons given above. It is rather an arcane
> point, and I probably shouldn't have mentioned it.

Ok, I see that now :-(

> >Well I can see a lot of documentation that would need to be changed ..
but I
> >can't see any technical problems with just doing it ... can you?  On the
> >other hand I can see a lot of other things that could start happening
very
> >simply.  For example, we could just start talking about concepts like
"The
> >Coherence Theory of Truth" or "Pat Hayes"  without having to make a URIs
for
> >them.
>
> Well no, because all you would have is the ability to talk about
> those character strings, not about what they might refer to. That's
> the cost of having tidy-literal graphs: it kind of forces you to lock
> down a single fixed global meaning for each literal.

Ok, I see that now.  With the (current?) assumptions of the WG, apparently
you have effectively eliminated the use of literals as subjects :(     I
hesitate to mention, you could have gone ziggeing instead of zagging.   The
WG could have used the literal subject as denoting values instead of
lexical forms.  This would have allowed moving the datatyping to the other
side of the node, eliminating all the do-ce-doe with the extra Bnode, and
allowing a more natural datatyping of the actual literal.

<:Jenny> <ex:age> "13"
"13" <rdf:type> <DecimalNumberRepresentedByString>
<ex:age> <rdfs:range> <DecimalNumberRepresentedByString>

See mentograph:
http://robustai.net/mentography/rdf_literal_subjects2.gif

Advantages:
*) allows literals to be subjects
*) handles all idioms (I think)

Disadvantages:
*) forces changing doc and syntax to allow literal subjects
*) allows incompatible rdf graphs that would need to be converted prior to
merging.

But I doubt anyone will want to take this seriously after all the vested
effort the other way around.

Seth Russell
Received on Monday, 25 February 2002 14:11:30 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 21 September 2012 14:16:30 GMT