
The 
Webometrics Ranking of World Universities has created a new 
Ranking of Repositories, but in the 
announcement,  a few salient points are overlooked:
Yes, as noted, the three first ranks go to "thematic" (i.e., discipline- or or subject-based) 
Central Repositories (CRs): 
(1) Arxiv (Physics), 
(2) Repec (Economics) and 
(3) E-Lis (Library Science). That is to be expected, because such CRs are fed from institutions all over the world.
But the fourth-ranked repository -- and the first of the university-based 
Institutional Repositories (IRs), displaying only its own institutional output  -- is 
(4) U Southampton EPrints (even though Southampton's University rank is 
77th).  
Moreover, the fifteenth place repository -- and the first of the department-based IRs -- is 
(15) U Southampton ECS EPrints (making it 10th ranked even relative to university-wide IRs!).
None of this is surprising: In 
2000 Southampton created the 
world's first free, OAI-compliant IR-creating software -- 
EPrints -- now used (and imitated) worldwide.   
But Southampton's ECS also adopted the world's 
first Green OA self-archiving mandate, now also being emulated worldwide. And that first mandate was a 
departmental mandate, which partly explains the remarkably high rank of Southampton's ECS departmental IR.  
But these repository rankings (by 
Webometrics as well as by 
ROAR) should be interpreted with 
caution, because not all the CRs and IRs contain full-texts. Some only contain metadata. Southampton's university-wide IR, although 4th among repositories and 1st among IRs, is still 
mostly just metadata, because the university-wide mandate that U. Southampton has since adopted still has not been officially announced or implemented (because the university had been preparing for the 
2008 Research Assessment Exercise returns). As soon as the mandate is implemented, that will change. (Southampton's ECS departmental IR, in contrast, mandated since 2002, is already virtually 100% full-text.)
But the moral of the story is that what Southampton is right now enjoying is not just the well-earned visibility of its research output, but also a 
competitive advantage over other institutions, because of its 
head-start, both in creating IRs and in adopting a mandate to fill them. (This head-start is also reflected in Southampton's unusually high 
University Metrics "G Factor," and probably in its University 
Webometric rank too. 
Citebase is likewise constrained by who has and has not begun to systematically self-archive. And 
Citeseer has alas stopped updating as of about 
2003.) 
I am not saying all this by way of bragging! I am 
begging other institutions to take advantage of the fact that it's still early days: Get a competitive head start too -- by creating an IR, and, most important of all, by adopting a 
Green OA self-archiving mandate!
Stevan Harnad
American Scientist Open Access Forum