Tim Brody, Citation Impact of Open Access Articles vs. Articles available only through subscription ("Toll-Access"), a preprint in progress. The best compilation of data to date on the effect of OA on citation impact in physics and mathematics for the decade 1992-2003. Excerpt: 'The data come from the Institute for Scientific Information (ISI) CD-ROM citation database, which covers the main journals in all fields, and from the OA Physics/Mathematics Archive http://arxiv.org/ where authors can self-archive their articles to make them Open Access (OA). The method was to take all the physics and mathematics articles indexed by ISI from 1992-2003 and first calculate how much each article is cited. Then all these articles are divided into those that are and are not in Arxiv, hence are or are not OA. The OA advantage is then calculated from a comparison of the citation counts for the OA versus the non-OA articles: 100(OA/non) - 100% (OA divided by non-OA citation counts, minus 100%). This gives the percentage by which citation impact is altered, positively or negatively, by making the article OA (by self-archiving it in Arxiv). As will be seen, virtually all of the OA impact effect (red) is positive: OA enhances citation impact substantially, sometimes by several hundred percent. This is to be expected, because increasing accessibility increases rather than decreases potential usage.'
Brody and the six other members of his project are extending their study beyond physics and mathematics. They are not only collecting and analyzing data from a large number of other fields. They are organizing the data behind an interactive interface allowing users to select any combination of research specializations and display graphs of their data on the same page. For example, here's the page on geriatrics, acoustics, and linguistics.
Posted by
Peter Suber at 1/06/2005 09:58:00 AM.
The open access movement:
Putting peer-reviewed scientific and scholarly literature
on the internet. Making it available free of charge and
free of most copyright and licensing restrictions.
Removing the barriers to serious research.
