Rachel said:
> 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??
Andy said:
> 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.
My understanding is that because of the way XML Schema works with XML
namespaces, it's not possible to model elements/attributes from two
namespaces within one XML Schema. So we will necessarily have a minimum
of two "base schemas" for DCMI, one each for the elements in the two
namespaces http://purl.org/dc/elements/1.1/ and
http://purl.org/dc/terms/ This contrasts with RDF Schema where you
could put the descriptions of the terms in the two namespaces in one
file (if you really wanted to do so!)
So I don't think Rachel's requirement can be realised directly.
And following Carl and Andy's messages at
http://www.jiscmail.ac.uk/cgi-bin/wa.exe?A2=ind0203&L=dc-architecture&F=
&S=&P=8602
http://www.jiscmail.ac.uk/cgi-bin/wa.exe?A2=ind0203&L=dc-architecture&F=
&S=&P=8322
I think we're saying that, given the need for different datatyping
requirements for using elements from the _same_ namespace in _different_
application contexts, there may be a requirement for multiple XML
Schemas to represent the terms in one namespace.
What I'm still not sure about is whether these multiple schemas for,
say, http://purl.org/dc/elements/1.1/ are to be completely independent
of each other, or whether we should try to build explicit relationships
between them, or more specifically between the datatypes used within
them.
My understanding is that we can do the former quite easily, but trying
to do the latter introduces some (for me, at least) quite difficult
questions of datatype hierarchies.
Cheers
Pete
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