DC comments & questions

[Tony Linde]

One more comment before I go do something interesting for the last couple of
hours of the weekend...

I was just checking out OAI and in the 'Guidelines for Repository
Implementers' at
http://www.openarchives.org/OAI/2.0/guidelines-repository.htm it states:

'Repositories are not required to store their metadata in DC; DC is
something that is frequently "converted to", rather than "stored in". Many
repositories store their metadata in some other format, and dynamically
convert to DC in response to harvester requests.'

Which is pretty much what I have been arguing for. 

Cheers,
Tony. 

> -----Original Message-----
> From: owner-registry at eso.org [mailto:owner-registry at eso.org] 
> On Behalf Of Tony Linde
> Sent: 05 October 2003 13:09
> To: registry at ivoa.net; Bob Hanisch; 'Roy Williams'
> Subject: DC comments & questions
> 
> 
> Hi Bob, Roy et al,
> 
> I checked out PDS profiling yesterday and their use of DC. It 
> is similar to ours but they're using their own element 
> descriptive language (keyword=value
> based) where we're using xml schema. PDS cannot therefore use 
> inheritance and other features of xml schema that we're 
> making use of. 
> 
> PDS have implemented a sort of registry browser with 
> cross-links between missions, datasets, hosts, instruments 
> etc and with links from keywords to help text and 
> enumerations. A really good utility that we'd do well to emulate.
> 
> The PDS seem to only have ued Identifier, Title and Format 
> from DC. It also seems a fairly recent adoption as many of 
> the actual products I found did not have these as part of the 
> metadata but I might have been looking at the wrong things.
> 
> I also looked into DC closer today and have a few questions:
> 
> 1. I see in the schemas that DC-related elements are 
> annotated with <vm:dcterm> elements - how are these to be 
> used? And ought we to be namespacing to DC instead?
> 
> 2. Where, with things like identifier and coverage, we have 
> structured data while DC mandates simple string data, how and 
> where does this conversion take place?
> 
> 3. Should we, like PDS, block all our DC terms into a single 
> complex type? 
> 
> 4. If so and where our metadata does not map to a simple 
> string, should we put the DC term in here and mandate that it 
> is not captured from the user/dataaset but is constructed 
> from the structured metadata in some way (as we've defined 
> the way of turning an Identifier into a URI)?
> 
> 5. Finally, how do we use DC? When metadata from our 
> registries is harvested to non-astro sites, what do they 
> take: only the DC terms or all of the metadata? And how is 
> OAI related to DC?
> 
> Cheers,
> Tony. 
> __
> Tony Linde                       Phone:  +44 (0)116 223 1292
> AstroGrid Project Manager        Fax:    +44 (0)116 252 3311
> Dept of Physics & Astronomy      Mobile: +44 (0)7753 603356
> University of Leicester          Email:  ael at star.le.ac.uk
> Leicester, UK   LE1 7RH          Web:    http://www.astrogrid.org
> 
>