On Fri, 8 Mar 2002, Rachel Heery wrote:
> On Fri, 8 Mar 2002, Andy Powell wrote:
>
> >
> > I stand by the assertion in section 4.1 of
> >
> > http://www.ukoln.ac.uk/metadata/dcmi/dc-xml-guidelines/
> >
> > that in simple DC "each value [of a property] is a literal string".
> >
> > The desire to embed more complex structured information into a DC element
> > value is fine... but it is *not* 'simple DC' (IMHO).
> >
> > The XML schema under discussion is explicitly an XML schema for 'simple
> > DC'. Therefore, it would be inappropriate for the schema to allow
> > anything other than strings as element values. Therefore we should revert
> > to the originally proposed XML schema.
>
> If I understand correctly you are suggesting a different restriction on
> the 15 core DC elements whether they are used as part of 'simple' or
> 'qualified' DC? That does not seem a very robust approach?
In my view 'simple DC' is an application profile. It is a particular
usage of 15 DC elements in a particular way - as outlined in the DC XML
guidelines document
http://www.ukoln.ac.uk/metadata/dcmi/dc-xml-guidelines/
> I am not confident that particular implementations will be able to
> categorise themselves as 'simple' or 'qualified' ?
If the application uses the 15 elements in the particular way described in
the document above, then it is a 'simple DC' application.
> From DCMI view:
>
> What I would like to see is one XML schema for all DC terms... given that
> we now have elements in 2 different namespaces I think we have to accept
> the need for a schema containing all terms.... surely it will be a
> nonsense to have a schema with qualifiers and one element??
I don't see any direct relationship between namespaces and schemas.
Namespace are abstract concepts that partition our view of a set of
elements. XML schemas define particular applications, and may take
some or all elements from one or more namespaces as appropriate.
What we are talking about here are small(ish) XML schema building blocks,
that make it easier for other people to put together their own
'applications' (in the form of XML schemas) using the schema import
mechanism.
If a schema representing all DCMI terms is a useful building block, then
fine, lets create an XML schema for it that others can import. But I'm
not convinced it is BTW.
All I'm suggesting at the moment is that we can give people one very
small, very simple building block that helps them build 'simple DC'
applications - and that we can do this now at very little cost and with no
commitment that we won't do something more complex and better in the
future.
If the building blocks don't help, then people are, of course, free to
start building from scratch anyway.
Andy.
> Rachel
>
>
> >
> > Here are two arguments to support this position:
> >
> > 1) If the abstract model for 'simple DC' that we proposed above is wrong,
> > i.e. if the simple DC model allows element values that are more complex
> > than literal strings, then we can *not* implement 'simple DC' in HTML meta
> > tags.
>
> ... is it not acceptable that HTML meta tags will only allow 'limited'
> implementation? One just accepts that HTML syntax does not offer same
> flexibility as XML or RDF/XML. Otherwise we are constrained by one
> syntax??
>
> Rachel
>
Andy
--
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