[OAI-implementers] DSpace OAI-PMH support changes, issues

herbert van de sompel herbertv at lanl.gov
Mon Jun 21 13:07:46 EDT 2004

Tansley, Robert wrote:

>>On Thu, 10 Jun 2004, Tansley, Robert wrote:
>>>- Are Handles appropriate IDs for the OAI metadata records? 
>>>Originally, it seemed pointless to me to use anything else; forcing 
>>>people to jump through yet another hoop to get yet another 
>>unique ID 
>>>to get set up.  However, on occasion people have indicated they'd 
>>>rather use an oai: prefixed identifier.  If anyone can 
>>offer reasons 
>>>and suggestions either way I'd appreciate it.
>>Aside from the possibility of changing ids to get around the 
>>changing sets problem, I can't see why an oai-identifier 
>>would be preferred to a handle.
> One potential scenario I've thought of is where >1 DSpace contains the same item, with the same Handle (resource ID).  Each DSpace might have different/additional metadata though and in any case probably shouldn't use the same ID for OAI-PMH.  So, perhaps an easy way forward is to use an OAI identifier of the form:
> oai:(dspace hostname):(handle)
> E.g.
> oai:dspace.mit.edu:1721.1/1234


I think the above makes _a lot_ of sense.  As a matter of fact, if I am not 
mistaken, the American Physical Society does something along the same lines by 
making their doi's part of an oai-identifier.

One firm advantage to the above that I can see is the clear distinction that is 
made between the identifier of the resource (handle) and the identifier of the 
OAI-PMH item (oai-identifier) that gives access to metadata about the resource. 
  The more elaborate services that we will start building based on materials in 
Institutional Repositories, the more it will become important to clearly 
distinguish between the identifier of a resource, the identifier of metadata 
that describes the resource, the identifier used in the OAI-PMH to harvest 
metadata pertaining to the resource.  At least we should be aware of those 
differences.  Indicating that distinction through an appropriate choice of 
identifiers doesn't hurt the least.

Generally speaking, I would like to take advantage of this thread to emphasize 
the importance of doing the right thing re identifiers used in the OAI-PMH. 
Recently, at conferences and meetings, I have seen a lot of really problematic 
implementations of OAI-PMH identifiers, including OAI-PMH identifiers that:
* do not follow URI syntax
* do not aim for some global uniqueness
Such a sloppy use of OAI-PMH identifiers is going to eventually cause huge 
problems, for example, when trying to build services on top of a global network 
of Institutional Repositories.  I recommend re-reading what the protocol 
document says re OAI-PMH identifiers: 



Herbert Van de Sompel
Digital Library Research & Prototyping
Los Alamos National Laboratory, Research Library

More information about the OAI-implementers mailing list