For researchers or OA advocates (or detractors!) who are interested in the current state, growth rate and distribution of Open Access Repositories (or Archives) worldwide, ROAR (http://archives.eprints.org/), the Registry of Open Access Repositories (created by Southampton doctoral student Tim Brody as part of his thesis, and for the Eprints and jOpCit projects) allows anyone to generate growth charts by archive type, or by individual archive. It can also rank-order archives by the number of OAI records they currently contain (i.e., their size).
ROAR is a gold-mine of current, cumulating data, ripe for anyone enterprising enough to want to report an up-to-date quantitative analysis of how OA IRs are progressing today, and where.
I also take this opportunity to remind all OA Archives and OA IRs to please *register* with ROAR so you too can be counted, and your content growth tracked.
The size and growth data are classified by the type of Archive:
(i) Distributed Institutional/Departmental Pre-/Postprint Archives (275),
(ii) Central Cross-Research Archives (69)
(iii) Dissertation Archives (e-theses) (62)
as well as
(iv) database Archives (e.g. research data) (10)
(v) e-journal/e-publishing Archives (53)
(vi) demonstration Archives (not yet operational) (24)
(vii) "other" Archives (non-OA content of various kinds) (79)
The archives can also be classified by country, and by the software they use.
One caveat: The number of OAI records does not necessarily correspond to the actual number of full-text articles or dissertations in the IR! For many archives the records are still only the metadata (author, title, etc.), not the full-texts themselves. ROAR will soon have a way of counting only full-texts, separately. Meanwhile, contents will have to be sampled to estimate what percentage of the records are just metadata and what percentage are full-texts. (Some of the central archives are full-text only, and many of the advanced institutional archives, especially the ones with self-archiving mandates, are also mostly full-text.)
Even among full-texts, not all may be OA's target contents (journal article postprints and preprints plus dissertations). They may be documents of other kinds (teaching materials, multimedia, "gray literature," even administrative records). ROAR does not register archives that *only* contain metadata; among archive types (i)-(iii), ROAR also does not register archives that do not target OA content -- preprints, postprints, theses -- at all.
Stevan Harnad (U Southampton)