[OAI-implementers] DOI and OAI experiences anyone?

Alan Kent ajk@mds.rmit.edu.au
Thu, 7 Aug 2003 10:08:28 +1000


I have been reading up recently on DOI a bit more closely, and looking
and the 'Handle System' (www.handle.net). I was wondering what experiences
there were out there. Maybe this is what D-space and similar projects
address. The specific situation I am trying to come up with a "good"
solution for is below. But I am interested in generic solutions and
the "best" way to solve these sorts of problems as I think its relevant
in all sorts of situations. Sorry, the following wanders around a bit
before it gets back to OAI.

I actually started looking at SCORM. The idea of SCORM is you develop
small reusable units of learning material (lets call them a 'lesson')
and then assemble larger 'courses' etc from those units. SCORM talks
about 'content repositories' but does not really seem to have addressed
the issues properly (yet). I was looking at it from a utopian point of
view (not worrying about implementation practicalities).

SCORM uses XML encoded metadata (based on IMS) to describe each reusable
unit. Good stuff for searching. It even recommends a way to bundle up
a set of files into a single ZIP file to down load. So you end up with
single files that have XML encoded metadata describing the content of
the file.

Each unit however needs to make references to other units. For example,
courses need to reference lessons. You can use a HTTP URL to point to
it on some site, but this is pretty location specific.

For example, consider a University A that authors SCORM material with
copyright restrictions that it sells rights to for other organisations.
Or they may only publish the metadata on their web site (or via OAI).
University B buys a subset of the material (eg: two courses where some
of the lessons in that course are shared between different courses).
To avoid network bills etc, University B wants to locate all the content
locally - they dont want to access the material directly from University A's
web site.

So it makes sense to me to use a location independent identification
scheme such as DOI to do references. (I guess PURLs are an option too.)

This is where it gets a bit more interesting. Within University B, it
wants to resolve the DOI to a local copy of the file. It does not want
anyone external to the University however to use that resolution. So
I guess it wants a 'DOI Proxy Server' which allows additional location
information to be associated with DOIs that it has access to (??).
Or if using PURL, you want something like a HTTP proxy server that
can intercept the reference to the external resource and redirect it
to a local copy of that resource.

So how does OAI fit in?

Well, it makes sense to me to publish the metadata records via OAI.
Then authors can publish metdata information about lessons or courses
they develop for consumers to find (and purchase etc). I was then
thinking what OAI identifier to use for the metadata records. I am
guessing it would make sense to use the DOI as the OAI identifier.

This lead me to wonder (and this is treading on thin ice!) whether
an OAI repository implementation could actually be the local cache
instead of using a special DOI or HTTP proxy server. If someone asks
for a specific identifier and its not in the local repository, go out
and try to find it and then cache the value locally. This feels a bit
unclean however - its not using OAI for its intended purpose. It also
does not address the issue of the real content (instead of just the

Then it gets even more interesting when you don't want to rely on
having external network access. (SCORM was originally funded I believe
by DoD and I could imagine having closed environments there.) This
makes HTTP URLs to me a risky sort of way to go. So a DOI handle
server that can run standalone or connected to the Internet, that can
add local information to information returned by public hosts?

Is this the whole idea of digital libraries in the first place?

Any pointers to relevant projects or papers would be greatly appreciated.
I don't want to reinvent the wheel.

Alan Kent (mailto:Alan.Kent@teratext.com.au, http://www.mds.rmit.edu.au/~ajk/)
Project: TeraText Technical Director (http://teratext.com.au) InQuirion Pty Ltd
Postal: Multimedia Database Systems, RMIT, GPO Box 2476V, Melbourne 3001.
Where: RMIT MDS, Bld 91, Level 3, 110 Victoria St, Carlton 3053, VIC Australia.
Phone: +61 3 9925 4114  Reception: +61 3 9925 4099  Fax: +61 3 9925 4098