Open access and openly accessible: a study of scientific publications shared via the internet.
OBJECTIVE
To determine how often reprints of scientific publications are shared online, whether journal readership level is a predictor, how the amount of file sharing changes with the age of the article, and to what degree open access publications are shared on non-journal websites.


METHODS
The internet was searched using an application programming interface to Google, a popular and freely available search engine.


METHODS
The proportion of reprints of journal articles published between 1994 and 2004 from within 13 subscription based and four open access journals that could be located online at non-journal websites.


RESULTS
The probability that an article could be found online at a non-journal website correlated with the journal impact factor and the time since initial publication. Papers from higher impact journals and more recent articles were more likely to be located. On average, for the high impact journal articles published in 2003, over a third could be located at non-journal websites. Similar trends were observed for the delayed or full open access publications.


CONCLUSIONS
Decentralised sharing of scientific reprints through the internet creates a degree of de facto open access that, though highly incomplete in its coverage, is none the less biased towards publications of higher popular demand.
Wren
Jonathan D
JD
Advanced Center for Genome Technology, Department of Botany and Microbiology, University of Oklahoma, 101 David L. Boren Blvd, Rm. 2025, Norman, OK 73019, USA. Jonathan.Wren@OU.edu
D015706:Bibliometrics; D016247:Information Storage and Retrieval / Q000592:standards*; D020407:Internet / Q000592:standards / Q000706:statistics & numerical data*; D010506:Periodicals as Topic / Q000706:statistics & numerical data / Q000600:supply & distribution*; D011643:Publishing / Q000600:supply & distribution*; D012680:Sensitivity and Specificity