Online access = more citations

Free online availability of scientific articles increases the likelihood of papers getting cited, especially in the developing world and in the biomedical sciences, according to a new linkurl:study;http://www.sciencemag.org/cgi/content/abstract/323/5917/1025 published today in __Science__. The question of whether open access drives citations has been hotly contested among scientists, policymakers, and editors, with several recent studies coming down on different sides of the debate. In the most extensive study to date -- covering around 26 million articles from more than 8,000 journals published from 1998 to 2005 -- University of Chicago sociologist linkurl:James Evans,;http://home.uchicago.edu/~jevans/ together with neurobiology grad student linkurl:Jacob Reimer,;http://www.cinnresearch.org/Personnel/Hatsopoulos2.html found that making an article freely available on the internet increased the number of citations, but only by about 8%, which was far less than some previous claims. When the authors looked just at poorer countries, however, they found that the influence of open access was more than twice as strong. For example, in Bulgaria and Chile, researchers cited nearly 20% more open access articles, and in Turkey and Brazil, the number of citations rose by more than 25%. Free online availability "is not a huge driver of science in the first world, but it shapes parts of science in the rest of world," Evans told __The Scientist__. "Scientists and scholars in poorer countries are disproportionately citing articles that are freely available to them." "The results make a lot of sense," linkurl:Gunther Eysenbach,;http://yi.com/home/EysenbachGunther/ a health policy and e-health researcher at the University of Toronto who was not involved in the research, told __The Scientist__. "In countries with lower income, the [open access] effect is bigger than in countries where researchers have access to the literature anyway -- that's quite intuitive." linkurl:Stevan Harnad,;http://www.unites.uqam.ca/cnc/en/profs/harnad.htm an open access advocate and cognitive neuroscientist at the University of Quebec at Montreal who was not involved with the study, said that the authors should have compared public and private institutions closer to home to test whether the same effect was true in the developed world. "[Evans] looked at the big picture, but he could have cut the cake a bit finer and found the same effects if he compared the Harvards and the have nots," Harnad told __The Scientist__. "It's a shame that with such rich data he didn't look at other such important and pressing questions." Free online access conferred the greatest citation advantage in the life sciences, and no significant influence in three areas -- chemistry, physics and the social sciences -- which the authors chalked up to a culture of pre-print databases and personal archiving. Although open access had a modest overall influence, commercial online availability had an even greater effect. This indicates that most researchers are turning to the internet to find papers, though they may rely largely on institutional subscriptions, said Evans. "The larger influence is of things being online," whether commercially or not. linkurl:Philip Davis,;https://confluence.cornell.edu/display/~pmd8/resume a Cornell University grad student in science communications who also studies the effects of open access on citation records, praised the article's size and breadth, but noted that Evans "can't measure the article-level details, he can only look at the journal level." The study lumped together articles from entire journal volumes, which overlooks author-pay models that make some but not all articles in a journal freely available, Davis noted. What's more, not all articles are created equal, Davis argued. In a linkurl:paper;http://www3.interscience.wiley.com/journal/121421651/abstract published last month in the __Journal of the American Society for Information Science and Technology__, Davis showed that much of the citation benefit of open access articles in 11 biomedical journals could be explained by article characteristics such as number of authors and page length, suggesting that higher quality articles are more likely to be made freely available. The authors of the current study "assume that they're measuring access but they're really measuring something else," Davis told __The Scientist__. "The very methodology leaves the question open as to whether the results could be explained by confounding effects." Evans dismissed Davis' criticism. His paper's methodology controlled for these factors by using "fixed effects models," he said. The study compared, for example, articles published in __Science__ in 2003 and cited in 2004 -- when the journal was still under its one-year embargo period -- to the same articles cited in 2006, at which point the papers were freely available. When he didn't use fixed effects and compared journals to each other, Evans noted, the open access effect was much larger -- by at least an order of magnitude -- and the numbers of authors and pages significantly influenced the results. "In my reported estimation this is not the case." __Image: Jupiter Images__ **__Related stories:__***linkurl:More articles, fewer citations;http://www.the-scientist.com/blog/display/54839/ [18th July 2008]*linkurl:A new proposal for citation data;http://www.the-scientist.com/blog/display/54402/ [4th March 2008]*linkurl:Open access brings more citations;http://www.the-scientist.com/blog/display/23448/ [16th May 2006]

Online access = more citations

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