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Re: LANG: Moving issues 5.6 and 5.14 forward

From: Jeff Heflin <heflin@cse.lehigh.edu>
Date: Tue, 24 Sep 2002 15:49:47 -0400
Message-ID: <3D90C1DB.196B9933@cse.lehigh.edu>
To: Massimo Marchiori <massimo@w3.org>
CC: WebOnt <www-webont-wg@w3.org>

Massimo Marchiori wrote:
> 
> The point is that in order to find a solution, we need (well, it would be better, say) to know better what the meaning of imports
> and versioning are.
> At high-level, there are two choices, as been discussed, to include these things:
> + put the thing "in RDF"
> + put the thing "outside RDF"
> These don't come for free, on either sides. Since we're on it, the "outside RDF" has as major impact the fact that, as we're using
> RDF as exchange syntax, the "thing" cannot be exchanged, and it's bound to its local instantiation.
> Now, don't get me wrong, two weeks ago on the call I've advocated heavily, with Peter, against the dangers of putting things "in
> RDF", so I'm not saying the other spectrum is the one to choose too, just pointing out the implications.
> So, back to the issue, putting things "out", while nicely avoiding some RDF troubles, has some drawbacks too. Whether these are real
> drawbacks or not, depends on the meaning of the "thing", so I don't think we can easily choose one or the other (or similar
> variations) before we have clear what we need the "thing" to be.

Massimo, I've given intuitive definitions of these things, and we've
seen some proposals for formal definitions, even a use case for
versioning. Furthermore, the requirements document quite clearly points
out the need for both imports and versioning. I chose to attack the
domain of discourse problem because a) it seems like were closer to an
agreement on that than on "how we define imports" and b) we must answer
to the domain of discourse question before we can come up with a precise
definition of imports.

> -M
> 
> ps
> Just to illustrate the kind of possible reasoning's:
> For instance, do we really need explicit versioning in v1 (explicit versus implicit versioning using namespaces)?

Yes, see [1] for a use case. Also see Jim's message [2] which states
that how to handle versioning is a frequently asked question about the
Semantic Web. Oh, and then there's our requirements document. 

> If we do, then
> shouldn't it be "in RDF"? 

Why? So far, I've heard many people argue no, and you are the first to
say that it should.

>If we don't, then the "thing" is just the import,

That does not follow at all.

> and at then point, once clear what import we need, it
> might end that we can just use XInclude, as Raphael nicely showed, and therefore don't get trapped in the issue at all :)

For reasons I've mentioned elsewhere, I cannot live with the XInclude
solution. I have also heard a few others say this solution is
unacceptable.

Jeff

[1] http://lists.w3.org/Archives/Public/www-webont-wg/2002Sep/0302.html
[2] http://lists.w3.org/Archives/Public/www-webont-wg/2002Sep/0304.html
Received on Tuesday, 24 September 2002 15:49:52 GMT

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