An Introduction to the Search/Retrieve URL Service (SRU)
To articulate and draft a reference model describing digital library services
To propose a number of light-weight protocols along the lines of OAI-PMH as a means to facilitate
digital library services
To implement a select number of digital library services exemplifying the use of the protocols
OCKHAM proposes a number of initial services to be implemented:
a registry service
an alerting service
a browsing service
a pathfinder service
a search service
a metadata conversion service
a cataloguing service
Notre Dame is taking the lead in developing the alerting service -- a sort of current awareness applica- tion allowing people to be kept abreast of newly available materials on the Internet. This is how the ser- vice will work:
An institution (read 'library'), will create a list of OAI data repositories (URLs) containing informa- tion useful to its clientele.
These URLs will be fed to an OAI harvester and the harvested information will be centrally stored. Only a limited amount of information will be retained, namely information that is no older than what the hosting institution defines as 'new.'
One or more sets of MARC records will be harvested from library catalogues and saved to the cent- ral store as well. Again, only lists of 'new' items will be retained. As additional data is harvested the older data is removed.
Users will be given the opportunity to create searches against the centralised store. These searches will be saved on behalf of the user and executed on a regular basis with the results returned via email, a Web page, an RSS feed, and/or some other format.
SRU URL's will be the format of the saved searches outlined in Step 4 above. These URLs will be con- structed through an interface allowing the user to qualify their searches with things like author names, titles, subject terms, free text terms or phrases, locations, and/or physical formats. By saving user pro- files in the form of SRU URLs, patrons will be able to apply their profiles to other SRU-accessible in- dexes simply by changing the host and path specifications.
The goal is to promote the use of SRU URLs as a way of interfacing with alerting services as unambigu- ously and as openly as possible.