[OAI-implementers] Sets in OAI-PMH and DSpace
Tue, 21 Oct 2003 15:50:18 -0400
I believe what you are proposing is perfectly legal, but there is no
implication in OAI that A:C has anything to do with B:C, and no way to
harvest collection C without specifying a community of A or B. Of course
the set description could explain all this and a group could come to
agreement as to how the sets were going to be used.
> -----Original Message-----
> From: Tansley, Robert [mailto:firstname.lastname@example.org]
> Sent: Tuesday, October 21, 2003 3:36 PM
> To: Hickey,Thom; email@example.com
> Subject: RE: [OAI-implementers] Sets in OAI-PMH and DSpace
> > The set structure in OAI is very simple, but also has almost
> > complete flexibility, so I'm sure you could encode any
> > relationships that DSpace is aware of in them. But the
> > retrieval on sets is quite limited, so it isn't clear what
> > good it would do.
> > I agree with Hussein -- keep them simple. For DSpace,
> > possibly a unique ID for each collection.
> My understanding was that sets could be flat or hierarchical;
> presumably this means a strict hierarchy, i.e. no node could
> have >1 parent -- is this correct? If so, DSpace could not
> expose the case where a Collection appears in two
> Communities, since the same Collection would have two
> setSpecs. However, thinking about it, maybe this is actually
> OK, since that Collection would effectively be two OAI sets
> with two separate setSpecs; for selective harvesting
> purposes, harvesters don't necessarily need to know that the
> two sets are in fact the same Collection.
> Here's a quick example in case this isn't clear... Collection
> C is contained in Community A and Community B:
> Community A Community B
> \ /
> \ /
> \ /
> Collection C
> The exposed OAI set structure would be:
> setSpec setName
> A Community A
> A:C Collection C
> B Community B
> B:C Collection C
> Is there any reason why the above might be 'illegal' in
> OAI-PMH? Might any harvesters get confused?
> P.S. sorry if cross-posting to dspace-tech & oai-implementers
> caused any duplication weirdness... I for one seemed to get
> about 6 copies of replies, I don't know whether that was the
> mailing lists or my client getting confused though!
> Robert Tansley / Hewlett-Packard Laboratories / (+1) 617 551 7624