On Thu, 7 Mar 2002, Carl Lagoze wrote:
> 1. We (DCMI) try to not put the cart before the horse (which it
> appears that OAI may have done by pushing a "simple dc XML schema")
> and go on a longer track to get this modeling right in XML. (OAI
> could continue as before to have its own simple dc xml schema without
> importing anything from dcmi).
> 2. We (DCMI) go ahead and define a base xml schema that simply states
> the dc terms and provides a base value of "any well-formed xml" - this
> is what I think Jane is advocating. In this case we could provide the
> basis for some later modeling on how to restrict these trees so that
> they are dumb-downable (or decide not to enforce this at all in a
> schema).
> 3. We (DCMI) make an easy stab at this by providing a base schema that
> a) allows a value of any xml subtree but b) requires a text value
> resulting in xml like the following:
Carl,
I'm replying to your earlier message (but I've seen all the subsequent
ones and hope I understand them!).
Your analysis above misses a forth possibility - that we stick with a
simple DC schema (as we originally proposed) that limits element values to
simple strings.
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.
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.
2) If the abstract model for 'simple DC' allows complex element values
then, as has been discussed on the list, we have to be able to dumb those
values down. What are we dumbing down to? 'Really simple DC'? 'Dumb
DC'? 'Dumber DC'!? Surely 'simple DC' is the bottom line in terms of
dumbing-down?
In conclusion, we should have an XML schema for 'simple DC' that restricts
element values to be of type 'string'. We should get that schema in place
now so that people (including the OAI) can start using it. We should move
forward with discussions about 'non-simple DC' separately - and part of
those discussions will be about whether we are discussing 'complex DC' or
'qualified DC' or something else! But it won't be 'simple DC'!
Andy
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