RE: handling metadata with multiple values

From: Gretchen Greene <greene-at-stsci.edu>
Date: Tue, 12 Aug 2003 12:56:17 -0400


This makes a lot of sense to me for readability and grouping of like items and it would be great if there was agreement on how this is handled to simplify metadata exchange between registries.

I also endorse the ucdList element and hope to see this added into the VOResource schema. This element would simplify mining metadata content to find potential data sets which will satisfy data value driven query. In other words a high level filtering capability.  

-Gretchen

-----Original Message-----
From: owner-registry-at-eso.org [mailto:owner-registry-at-eso.org] On Behalf Of Anita Richards
Sent: Tuesday, August 12, 2003 10:28 AM
To: registry-at-ivoa.net
Cc: Elizabeth Auden
Subject: Re: handling metadata with multiple values

Ah - in the AstroGrid Registry group we came to the opposite conclusion -
that for human maintenance of the registry entries for data sets, at least, it was easier for lists to be in container elements as it makes it
much easier to see (in a properly indented document) where one type of element ends and the next begins. There are some exceptions at present for 'very important' elements with short lists.

However you can call the items something more informative, for example

<ucdList>
<ucd></ucd>
<ucd></ucd>
<ucd></ucd>
<ucd></ucd>

</ucdList>

<instrumentType>
<instrument></instrument>
<instrument></instrument>

</instrumentType>

<coordinatePair>
<coordinate></coordinate>
<coordinate></coordinate>

</coordinatePair>

In the last example, I see that (if I understand correctly) the Space-Time
metadata schemas from Arnold use a single type e.g. "coord2ValueType"
to enter a pair of coordinates in a single element. I can see many advantages to that, but not all data may have both halves of the pair or some queries may not care e.g. all data above dec -20 - will this be more complicated to impliment in a search than if (say) RA and Dec were separate elements?

thanks
a
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Dr. Anita M. S. Richards, AVO Astronomer MERLIN/VLBI National Facility, University of Manchester, Jodrell Bank Observatory, Macclesfield, Cheshire SK11 9DL, U.K. tel +44 (0)1477 572683 (direct); 571321 (switchboard); 571618 (fax). Received on 2003-08-12Z18:57:07