Hi Jane,
Its not clear to me that there is a clear proposal for the number of schema (schemata?), except for the fact that there will be more than one. The one we know about at this time is "simple dc'. There may be a schema for qualified dc, the conceptual basis of which is [1], where qualification is fairly tightly constrained. The answer to whether there will be other schema for a much fuzzier area that you are calling complex dc is unclear.
Your message implies that such a schema is necessary for application profiles but that leads to a much more expansive view of applicaiton profiles than I understand. For example, it is possible to write a schema based on the simple dc schema for an app profile defined as "must include one dc creator element and on dc title element and three elements from FGDC". Your definition of application profile seems to include more complex structures such as dc elements rooting sub-trees comprised of elements from mixed namespaces. Its not clear to me that we understand this world yet and how to control it.
Finally, regarding anySimpleType: I had not heard of such an animal until your email but went and found it in the datatype part of the xml schema spec. I played with it in xml spy just to check it out. From my brief look around it indicates that it has no real effect on the derived instance documents relative to xs:string. Is then your intention to make it possible for deriving schema (those that import it) to have an adequate restriction base?
Carl
[1] http://dublincore.org/documents/2000/07/11/dcmes-qualifiers/
> -----Original Message-----
> From: Jane Hunter [mailto:[log in to unmask]]
> Sent: Sunday, March 10, 2002 7:15 PM
> To: [log in to unmask]
> Subject: Re: Public Comment on DC-simple XML Schema declaration within
> OAI
>
>
> Dear all,
>
> My original concern with using the 'string' datatype was not just with
> the need for more complex structured derivations but also with the
> inability to derive other simple and commonly-required datatypes such
> as URIs (for dc:identity) or dates (for dc:date) from 'string'.
>
> I'm by no means an XML Schema expert but, one suggestion is that you
> consider using 'anySimpleType' rather than 'string':
>
> http://www.w3.org/TR/xmlschema-2/#built-in-datatypes
>
> At least then users can derive some other useful datatypes.
>
> And just to clarify, the current proposal is to have 3 XML Schemas?
>
> 1. An XML Schema for 'simple DC' - using either 'string' or
> 'anySimpleType' for the element types
>
> 2. An XML Schema from which 'complex DC' and application profiles can
> be derived - using 'anyType' for the element types
>
> 3. An XML Schema for 'qualified DC'.
>
> jane
>
> > I'll add my pat on the back to this. I think that Andy has
> successfully put the cap on this discussion.
> >
> > I raised the xHTML possibility to test the waters on
> whether HTML falls into the realm of lingua franca that serve
> as 'appropriate literals' for DCMI. This was inspired by the
> fact that xs:string in xml land is not the good old 7-bit
> ASCII that we know and love but unicode, which is a big step
> up the complexity ladder. I wasn't sure that adding html
> tagging to that stepped out of bounds, but figured it was
> worth asking. I withdraw that shredded trial balloon.
> >
> > Moral of the story: you've got to draw the line somewhere
> and I think that Andy's argument is as good as it gets.
> >
> > Carl
> >
> > > -----Original Message-----
> > > From: Dan Brickley [mailto:[log in to unmask]]
> > > Sent: Saturday, March 09, 2002 4:55 AM
> > > To: [log in to unmask]
> > > Subject: Re: Public Comment on DC-simple XML Schema
> declaration within
> > > OAI
> > >
> > >
> > > This is one of the clearest articulations of the problem I've
> > > heard in a long while.
> > >
> > > We know how to deal with simple string values, and how to
> qualify them
> > > (subproperties and datatypes, in RDF-ese). We don't know
> yet how to
> > > preserve widearea interoperability and data re-use as we move
> > > from this
> > > realtively well understood realm towards more complex, highly
> > > strucured
> > > multi-namespace data exchange. It's OK, that's a
> difficult problem for
> > > everyone...
> > >
> > > Dan
> > >
> > > On Sat, 9 Mar 2002, Andy Powell wrote:
> > >
> > > > On Fri, 8 Mar 2002, Carl Lagoze wrote:
> > > >
> > > > > Andy, is there any reason in your mind why we should NOT
> > > allow xHTML
> > > > > in the values of the simple schema. My first
> reaction is that it
> > > > > opens the door sufficiently to allow things like MathML
> > > but does not
> > > > > push it wide open into unrestricted land.
> > > >
> > > > I'm not really sure... but my feeling is that 'simple DC'
> > > means simple
> > > > literal string values and *nothing* else.
> > > >
> > > > Here's my thinking...
> > > >
> > > > 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).
> > > >
> > > > XHTML carried in DC element values does *not* feel like
> > > 'simple DC' to me.
> > > > I completely agree that it would be a useful thing to be
> > > able to do (and
> > > > at least one of the services I'm involved in would like to
> > > be able to do
> > > > it!) - but I wouldn't call it 'simple DC' and I don't think
> > > support for it
> > > > should appear in a 'simple DC' XML schema.
> > > >
> > > > Finally, as an aside...
> > > >
> > > > It seems to me that the problems associated with trying to embed
> > > > structured content within DC element values is the aspect
> > > of DC that we
> > > > understand least currently. I think we now have a good
> > > understanding of
> > > > qualified DC in terms of element refinement and encoding
> > > schemes. But we
> > > > still don't know how to handle structured content very
> > > well. For example,
> > > > we have the rather messy situation in which it is not clear
> > > if the DCMI
> > > > Box encoding scheme is a 'formatted string' or an 'XML
> > > application' or
> > > > both. I think this stems from an acknowledgement that
> we can do some
> > > > things in XML-based applications that we can't do in text-based
> > > > applications but without being quite sure how to handle
> > > that properly in
> > > > practice.
> > > >
> > > > Andy.
> > > >
> > > > > > -----Original Message-----
> > > > > > From: Roland Schwaenzl
> > > > > > [mailto:[log in to unmask]]
> > > > > > Sent: Friday, March 08, 2002 1:17 PM
> > > > > > To: [log in to unmask]
> > > > > > Subject: Re: Public Comment on DC-simple XML Schema
> > > declaration within
> > > > > > OAI
> > > > > >
> > > > > >
> > > > > > > From [log in to unmask] Fri Mar 8
> > > 16:30 MET 2002
> > > > > > > content-class: urn:content-classes:message
> > > > > > > MIME-Version: 1.0
> > > > > > > X-MimeOLE: Produced By Microsoft Exchange V6.0.5762.3
> > > > > > > Thread-Topic: Re: Public Comment on DC-simple XML
> > > > > > Schema declaration
> > > > > > > within OAI
> > > > > > > Thread-Index: AcHGrDpz/EG80hNpQAmDGuSf4riG1QACWQMg
> > > > > > > Date: Fri, 8 Mar 2002 10:30:05 -0500
> > > > > > > From: Carl Lagoze <[log in to unmask]>
> > > > > > > Subject: Re: Public Comment on DC-simple XML Schema
> > > > > > declaration within OAI
> > > > > > > Comments: cc: Herbert Van de Sompel
> <[log in to unmask]>
> > > > > > > To: [log in to unmask]
> > > > > > > Content-Transfer-Encoding: 8bit
> > > > > > > X-MIME-Autoconverted: from quoted-printable to 8bit by
> > > > > > scarlett.mathematik.Uni-Osnabrueck.DE id QAA20116
> > > > > > >
> > > > > > > Roland,
> > > > > > >
> > > > > > > Regarding point 1: The prohibition as you state it sound
> > > > > > pretty draconian; seems like some of the people originally
> > > > > > motivated OAI (eprints folks) would want mathML. Remind me
> > > > > > again, is there a solution that allows things like
> mathML but
> > > > > > forbid arbitrary other XML?
> > > > > >
> > > > > > >
> > > > > >
> > > > > > Sure, you could (!) do that. W3C's xml-schema-primer has an
> > > > > > example, with content restricted to XHTML:
> > > > > > http://www.w3.org/TR/xml-schema-0 sec.5.5. It's
> the example
> > > > > > preceding the textType example.
> > > > > > In particular table 4 in that section is quite useful as
> > > > > > summary of built in facilities.
> > > > > > There's a similar technique with attributes.
> > > > > >
> > > > > > One could try: http://www.w3.org/1998/Math/MathML for a
> > > namespace URI.
> > > > > >
> > > > > > There's some use of MathML embedded into XHTML -
> > > > > > (cf. processContents="skip" in the example cited above)
> > > > > >
> > > > > >
> > > > > > rs
> > > > > >
> > > > > >
> > > > > >
> > > > > > > Carl
> > > > > > >
> > > > > > > I've copied to Herbert Van de Somple because the MathML
> > > > > > thing might be of concern to him also.
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > > -----Original Message-----
> > > > > > > > From: Roland Schwaenzl
> > > > > > > > [mailto:[log in to unmask]]
> > > > > > > > Sent: Friday, March 08, 2002 9:19 AM
> > > > > > > > To: [log in to unmask]
> > > > > > > > Subject: Re: Public Comment on DC-simple XML Schema
> > > > > > declaration within
> > > > > > > > OAI
> > > > > > > >
> > > > > > > >
> > > > > > > > Dears,
> > > > > > > >
> > > > > > > > with us it's now the time for reports rather than
> > > development.
> > > > > > > > I'll not be able to follow this discussion the
> coming week.
> > > > > > > >
> > > > > > > >
> > > > > > > > Let me try to summarize, what i understand
> currently from
> > > > > > the dc-xml
> > > > > > > > discussion.
> > > > > > > >
> > > > > > > >
> > > > > > > > 1. In OAi the use of dc:elements with the xml- simple
> > > > > > > > dataType "string" will (continue to) be required in
> > > > > > > > the mandatory part of OAi.
> > > > > > > > It could be, that OAi allows a dataType extension by
> > > > > > > > the xml:lang attribute.
> > > > > > > >
> > > > > > > > [In particular no mark-up from W3C's MathML or Ruby will
> > > > > > be allowed in
> > > > > > > > oai-dc records].
> > > > > > > >
> > > > > > > > 2. There are mixed views on (details of)
> > > requirements, design
> > > > > > > > and coding
> > > > > > > > for dcmi supported "plain-xml"-schemes.
> > > > > > > >
> > > > > > > >
> > > > > > > > Please correct me on mistaken points.
> > > > > > > >
> > > > > > > >
> > > > > > > > Best,
> > > > > > > > rs
> > > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > >
> > > > Andy
> > > > --
> > > > Distributed Systems, UKOLN, University of Bath, Bath,
> BA2 7AY, UK
> > > > http://www.ukoln.ac.uk/ukoln/staff/a.powell +44
> 1225 383933
> > > > Resource Discovery Network http://www.rdn.ac.uk/
> > > >
> > >
>
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