Hi all-

For the exchange listed below, I ended up not using <mods:extension>,
and instead fitting some of the information into a label attribute. 

We are, however, for a different project, using <mods:extension> to
record information about which of our project categories a specific
subject-type term falls into. A first draft of this schema can be found
at <http://www.dlib.indiana.edu/metadata/eviada/eviadacv/eviadacv.xsd>.
We ended up going with a local schema within <mods:extension> for this
type of data because we never could find a good way of recording for a
given term what vocabulary a term originally came from (a lot were from
LCSH) AND at the same time recording which of our local categories the
term belonged to (e.g., "Venue" "Culture Group" or "Theme"). So we're
recording this data in the format most useful for us underneath
<mods:extension>, and also recording them as subject terms (where
applicable, some belong in genre) in the MODS document proper (without
an indication of which project category the term is in), for
interoperability reasons. This isn't fully implmented yet, but that's
the plan, at least. :-)

This exact schema outlines our local categories so I'm not sure how much
use it will be outside of this project, but the idea of <mods:extension>
for subject categories more granular than MODS offers I think might be
useful to others.

Jenn

========================
Jenn Riley
Metadata Librarian
Digital Library Program
Indiana University - Bloomington
Main Library E170
(812) 856-5759
www.dlib.indiana.edu


________________________________

        From: Metadata Object Description Schema List
[mailto:[log in to unmask]] On Behalf Of Ruth Bogan
        Sent: Wednesday, January 12, 2005 10:49 AM
        To: [log in to unmask]
        Subject: [MODS] Using the <extension> element
	
	

                I'm interested in hearing about uses of the <extension>
element in MODS. I copied out a fairly recent exchange, because this is
the type of extension I am interested in. I also found a declaration of
MODS extension for dates that Oxford University uses at
http://www2.odl.ox.ac.uk/data/aaaaaa/schema/odl.xsd
<http://www2.odl.ox.ac.uk/data/aaaaaa/schema/odl.xsd> 

         

        Are there more examples out there? 

         

        Ruth

         
        Ruth A. Bogan
        Head, Database and Catalog Portal Management
        Rutgers University Libraries
        47 Davidson Rd., Busch Campus
        Piscataway NJ 08854
         

        Rebecca Guenther to Jenn Riley: 20041104

         

        Another alternative might be to use the <extension> element,
where you can use elements from another schema. Using that you could
point to the

        namespace for MIX and then use the MIX element.  Here is what it
would

        like like:

         

        <extension><CameraCaptureSettings xmls:

        "http://www.loc.gov/standards/mix/mix.xsd"
<http://www.loc.gov/standards/mix/mix.xsd> >

        then you would parse the data into its appropriate subelements
as detailed in MIX. (see: http://www.loc.gov/standards/mix/mix.xsd
<http://www.loc.gov/standards/mix/mix.xsd>  or the example at:

        http://www.loc.gov/standards/mix/instances/mix_test.xml
<http://www.loc.gov/standards/mix/instances/mix_test.xml> )

         

        Another alternative if you are just using this locally is to use
the

        <extension> element with your own local element, e.g.

        <extension><cameraSettings>100 f 4.5 TL</cameraSettings>

         

        The intent of extension is to either use a local element or
bring in one from another namespace. If the latter, including the
namespace allows it to validate against that other schema. If you just
use a local element, it doesn't validate the data under it.