Gary Masters wrote:
> Now, I read in InfoWorld (my favorite computer magazine for a long time
> now) thinks that XML "allows the document developer to create tags that
> describe the data, and optionally create a set of rules called Document
> Type Definitions." Now, to my untutored mind, this seems like DC.
...
> I don't know. If there is a quick and easy way to let me know the major
> advantages of DC over XML, I will be happy to learn them. My
> point to this
> note is to point out that better does not allways mean success. Alas.
> I know this one from experience.
Gary,
Infoworld is right... XML is pretty great, and pretty flexible. It's not,
though, really something you can compare in a meaningful way with Dublin
Core.
XML is a syntax; a way of marking up bits of text. Dublin Core is a set of
15 semantic concepts; 15 buckets into which text (marked up any way you
like) can be placed.
There is nothing to stop you marking up Dublin Core using XML, and shipping
your records around as DC in XML. Indeed, the CIMI Dublin Core metadata
testbed did just that with thousands of records. You could just start
typing, and stick Dublin Core into an XML file any old way, or you could
define one of those Document Type Definitions (DTD) that Infoworld talked
about, and add a bit more control to exactly how you had to enter your
metadata. There are pro's and con's to both approaches, as always. At CIMI,
they defined a fairly loose DTD and used that.
Dublin Core can be marked up in a lot of ways; the HTML <META> tag syntax we
often talk about is just one of them. Others include XML, IAFA templates,
proprietary database formats, etc.
You can go a step further, too, as the Data Model working group did, and
look at adding some richness and control to your XML encoding by using the
Resource Description Framework (RDF). This is basically an application of
XML aimed specifically at describing resources in a manner that aids their
discovery. See
http://www.ukoln.ac.uk/metadata/resources/dc/datamodel/WD-dc-rdf/ for the
Data Model group's take on one way in which Dublin Core might be used in
this environment. There, you get syntax (XML), structure (RDF-ish), and
semantics (Dublin Core).
Hope that helps,
Paul
-- dr. paul miller - interoperability focus - [log in to unmask] --
u. k. office for library and information networking (ukoln)
tel: +44 (0)1482 466890 mobile: +44 (0)410 481812
---------------------------- http://www.ukoln.ac.uk/interop-focus/ --
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