[OAI-implementers] Re: question about the date in OAI-PMH

[Mei Ran]

Simeon,

Thank you very much for your help!

--Mei
On Tue, 24 Sep 2002, Simeon Warner
wrote:

> On Tue, 24 Sep 2002, Mei Ran wrote:
> > Hi,
> >
> > I'm not sure if I'm right for all the dates in the OAI. would you like
> > to give me some help:
> >
> > 1. the earliestDatestamp in Identify response. is this refer to the
> > resource creation or modification time?
>
> The earliestDatestamp is a datestamp that is earlier than or equal to the
> earliest datestamp for any metadata RECORD in the repository. Datestamps
> in OAI refer to the last addition, delete or modification of RECORDS and
> not resources. (The metadata records themselves describe resources. The
> semantics of the metadata are outside the scope of OAI-PMH, they are
> defined, for example, by Dublib Core.)
>
> Definition of resource, item, record in OAI:
> http://www.openarchives.org/OAI/2.0/openarchivesprotocol.htm#Repository
> Definition of Identify response with earliestDate element:
> http://www.openarchives.org/OAI/2.0/openarchivesprotocol.htm#Identify
> Datestamps in OAI:
> http://www.openarchives.org/OAI/2.0/openarchivesprotocol.htm#DatestampsResponses
>
> > 2. the Date in metadata, DC. is this refer to resource creation or
> > modification time too?
>
> The metadata is about the resource, so yes broadly speaking.
>
> Definition of Date element in unqualified DC:
> http://dublincore.org/documents/1999/07/02/dces/#date
>
> > 3. the datestamp in the header of DC. I think this one should refer to
> > the creation or modification of the item in the repository, is that
> > right?
>
> The OAI record header is not part of the DC (or other format) metadata.
>
> See answer to 1). However, you now mention 'item' which is slightly
> different. In OAI-PMH v2.0 (change from v1.1) an item is conceptually
> some union or source of the all the metadata records corresponding
> to a particular identifier. No datestamp is exposed for items, just
> for the metadata records.
>
> In practice, it may be the case that the item is the thing inside the
> repository that has a datestamp. In that case all records disseminated
> from the item (all metadata formats) will have that datestamp.
>
> Definition of 'item' in OAI:
> http://www.openarchives.org/OAI/2.0/openarchivesprotocol.htm#Item
> Section 3 of the Repository Guidelines also notes some issues with
> datestamps:
> http://www.openarchives.org/OAI/2.0/guidelines-repository.htm
>
> Cheers,
> Simeon
>
>
> > Thank you very much for your help!
> >
> > Mei
> >
> > *******************************************
> > Mei Ran
> > Research Assistant
> > Computer Science Dept., Univ. of Tennessee
> > http://www.cs.utk.edu/~ran
> > Tel: (865) 974-6722
> > *******************************************
> >
>
>

******************************************************
Mei Ran
Research Assistant
Computer Science Dept, Univ of Tennessee, Knoxville
http://www.cs.utk.edu/~ran
Tel: 865-974-6722
******************************************************