On Wed, 27 Mar 2002, Rachel Heery wrote:
> However as I understand it that discussion was about how to encode
> an XML schema, rather than whether DCMI should use the exoression 'Simple
> DC' as a synonym for 15 elements (as opposed to 16 elements).
How could we agree on a 'Simple DC' XML schema without agreeing what
Simple DC means? The schema is simply a concrete instantiation of the
abstract concept isn't it? In any case, the discussion clearly went
beyond that particular schema, e.g.
<I said>
We need to have a shared understanding of what we mean by a 'simple DC'
application.
Currently, that understanding has to work across applications that are not
based on XML. I'm thinking here about applications that carry metadata
using non-XML encodings such as HTML4/meta, Z39.50/GRS-1, Z39.50/MARC, ...
Any two 'simple DC' applications should be able to exchange all their
metadata. Anything encoded in one 'simple DC' application, should be able
to be encoded in another with no loss of data.
'Simple DC' is our most dumbed-down form of metadata. It provides our
base level of interoperability between different services. (Simple DC is
the equivalent of the plain text rendered by, say, lynx - not the (X)HTML
page on which that rendering is based).
</I said>
The english text definition of 'Simple DC' in section 4.1 of
http://www.ukoln.ac.uk/metadata/dcmi/dc-xml-guidelines/
was clearly referenced a number of times during the discussion.
> At very least surely we need to define DC Simple outside these somewhat
> inaccessible specs (as Andy says at end of his mail, in glossary
> perhaps)??
The wording of the definition of Simple DC is (I would suggest) about as
simple as you are likely to get. As I've already said, I would be happy
to see the definition moved to another document. I doubt if it will be
possible to come up with such simple definition of 'unqualified DC' - you
cannot refer to 16 elements for example... 'unqualified DC' will become 17
elements next time a new top level DC element is added to the DC TERMS
namespace.
> It seems to me there are two likely options, and it would be helpful if we
> agreed which of these was the focus for existing and future future
> documentation. I think the criteria for decision could be clarity for
> non-expert, and fit with continued evolution of DCMI terms.
Separate definitions for 'Simple DC', 'Unqualified DC' and 'Qualified DC'
(as defined at http://www.ukoln.ac.uk/metadata/dcmi/dcxml/examples.html)
would fit with these aims and would fit in with current usage.
> Following on from this DC Simple would be a 'qualitative' statement
> meaning a non-complex usage of DC terms, but not a specific set of terms.
Simple DC is not a specific set of terms. It is an application profile
that consists of a specific set of terms (the 15 terms in the DCMES) and
an encoding of the language of the value.
> An XML schema might be suggested then as an 'example' of a DC simple
> implementation. I think this would then fit in with the somewhat
> contentious idea that DC Simple is an 'application profile'.
In what sense is it contentious?
> Personally I prefer Option One as it seems to me to allow for continued
> implementation of the DCMES v1.1 while not emphasising the historical '15
> elements'.
Your Option One is 'unqualified DC' and 'qualified DC'. I'm suggesting
'simple DC', 'unqualified DC' and 'qualified DC'. We agree on the meaning
of 'unqualified DC' and 'qualified DC' (I think). Is there a major
problem?
As I have said, 'simple DC' is already in use. Removing 'simple DC' now,
means modifying the XML guidelines document (I'm sure Pete and I can
handle that however frustrating it might be given the length of comment
period that we've had!). It might mean re-titling DaveB's XML/RDF
document? Most importantly, it means we no longer have a label for
metadata applications that use the 15 elements from the DCMES and provide
a mechanism for encoding the language of the value?
Andy
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