[OAI-implementers] Beginner questions

[Andy Powell]

On Tue, 8 Apr 2003, Tim Brody wrote:

> Identifier in the metadata is a Dublin Core identifier, identifier in 
> the header is a unique identifier within your repository.

The identifier in the metadata is the identifier of the resource being
described - it is often a URL for the resource.  The identifier in the OAI
header is the identifier of the OAI 'item' (essentially the identifier of
the metadata record(s) about the resource).

> Dublin Core is a list of unordered, repeatable string values (although 
> you should use proper URIs, ISO dates etc. where applicable).
> 
> See the Dublin Core docs for what Type, Format, etc. are:
> http://www.dublincore.org/documents/dces/

Note: the correct URL is

  http://dublincore.org/documents/dces/

dc:type indicates the 'genre' of the resource (text, image, ...).

dc:format indicates the something about the 'digital manifestation' of the
resource (e.g. the way it is encoded).

I would recommend that dc:format should be a MIME type (for digital
resources) and that you consider selecting the value of dc:type from the
DCMIType vocabulary at

  http://dublincore.org/documents/dcmi-type-vocabulary/

Repeat dc:type to indicate other (more specific) genres if necessary.

> (Dublincore.org seems to be down atm so I can't check that's the 
> description doc ...)
> 
> e.g.
> Header.identifier = "oai:myrepos:uniqueid10"
> 
> DC.identifier = "http://www.myrepos.com/item/10"
> DC.identifier = "oai:myrepos:unique10" (i.e. you could also include the 
> OAI identifier in the metadata)

I tend to to disagree with this.  The OAI identifier is *not* an
identifier of the resource being described - it is an identifier of the
OAI item - therefore it shouldn't be repeated in the DC description.

Finally, if you are describing eprints, then you might want to take a look
at

  http://www.rdn.ac.uk/projects/eprints-uk/docs/simpledc-guidelines/

for some DC usage guidelines.

Andy.

> DC.identifier = "New Order Journal, V202 30-40"
> DC.type = "Text"
> DC.format = "text/html"
> DC.date = "2002-04"
> and so on ...
> 
> All the best,
> Tim.
> 
> Venugopal Reddy Pally wrote:
> > Hi all,
> >    These questions may be very basic but I am a
> > beginner. So please bear with me.
> >    I am following oai_dc XML Schema for displaying
> > metadata of any Record in GetRecord or ListRecords
> > response. There is 'identifier' element both in header
> > and metadata of Record. So what is the difference
> > between identifier element in header and identifier
> > element in metadata ? Also, what are the elements -
> > Type, Format in metadata ?
> > Thanks,
> > Venu.
> > 
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> 
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Andy
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http://www.ukoln.ac.uk/ukoln/staff/a.powell       +44 1225 383933
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