Hi Anna and all,
Two points on this:
1. RDF does not stop you building nested structures, quite the opposite. So long as the structure goes node-arc-node (or Object-property-Object-property if you prefer) it can be nested as deep as you like. You can therefore have an XML structure that both vaildates against an XML Schema or DTD and is valid RDF (see http://www.prismstandard.org where they do this). This would be a good way to think about designing XML Schema based documents even if you had no intention of using RDF. 2. RDF is not a panacea. It would be crazy to try and describe documents with it when one should be use XHTML or some other document centric approach. It is good for 'metadata' (depending on what that is) though.
There seems to be a rumour going round that everything is going to be RDF starting next week. This is news to me!
It seems like a good idea to evaluate RDF as an interoperability mechanism between standards though and the use of LSIDs suggests heading in this direction to describe objects. Whether the objects themselves are encoded in RDF is something else.
All the best,
Roger
On 15/02/06, Anna Weitzman Weitzman@si.edu wrote:
Good points. I wonder if TDWG-TAG will be the place for this larger, conceptual discussion?
"Gregor Hagedorn" G.Hagedorn@BBA.DE 15-Feb-2006 7:51:45 AM >>>
One comment following from the GUID meeting is that I believe we need to
get
serious about being able to represent our data models in RDF. This means that the goal should indeed be for a "flat" (Darwin Core like) standard.
If
there are elements which hold nested complexity that we wish to
represent,
we should recognise that these are probably separate data objects which should be modeled as separable components (with their own "flat"
standards).
The top level object can then have a property whose value is the
identifier
for one of the lower level components. Even if we choose to compose rich documents with entire trees of object relationships, the underlying
model
should make these separations clear.
I am concerned about this, to me it seems to block the way into a future for scientific data exchange.
Flat list is great for advertising, (see e.g. DublinCore, DarwinCore or RSS), but not really for exchanging complex data.
Completely forbidding any object aggregation would mean that each measurement of a specimen has a stand-alone resource... Or each author in a publication (because authors have addresses, so they can not be just a list, the list elements have structure).
Where can we discuss this issue which goes far beyond the TDWG-LIT?
Gregor---------------------------------------------------------- Gregor Hagedorn *(G.Hagedorn@bba.de %28G.Hagedorn@bba.de* ) Institute for Plant Virology, Microbiology, and Biosafety Federal Research Center for Agriculture and Forestry (BBA) Königin-Luise-Str. 19 Tel: +49-30-8304-2220 14195 Berlin, Germany Fax: +49-30-8304-2203
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-- ------------------------------------- Roger Hyam Technical Architect Taxonomic Databases Working Group ------------------------------------- http://www.tdwg.org roger@tdwg.org +44 1578 722782 -------------------------------------