Institut des Sciences Cognitives, Université du Québec à Montréal, Montréal, Québec, Canada.
PLoS One. 2010 Oct 18;5(10):e13636. doi: 10.1371/journal.pone.0013636.
Articles whose authors have supplemented subscription-based access to the publisher's version by self-archiving their own final draft to make it accessible free for all on the web ("Open Access", OA) are cited significantly more than articles in the same journal and year that have not been made OA. Some have suggested that this "OA Advantage" may not be causal but just a self-selection bias, because authors preferentially make higher-quality articles OA. To test this we compared self-selective self-archiving with mandatory self-archiving for a sample of 27,197 articles published 2002-2006 in 1,984 journals. METHDOLOGY/PRINCIPAL FINDINGS: The OA Advantage proved just as high for both. Logistic regression analysis showed that the advantage is independent of other correlates of citations (article age; journal impact factor; number of co-authors, references or pages; field; article type; or country) and highest for the most highly cited articles. The OA Advantage is real, independent and causal, but skewed. Its size is indeed correlated with quality, just as citations themselves are (the top 20% of articles receive about 80% of all citations).
CONCLUSIONS/SIGNIFICANCE: The OA advantage is greater for the more citable articles, not because of a quality bias from authors self-selecting what to make OA, but because of a quality advantage, from users self-selecting what to use and cite, freed by OA from the constraints of selective accessibility to subscribers only. It is hoped that these findings will help motivate the adoption of OA self-archiving mandates by universities, research institutions and research funders.
作者将自己的最终草稿自行存档，以供在网络上免费获取（“开放获取”，OA），从而补充订阅获取出版商版本的权限，这些文章的被引频次明显高于同一期刊和年份中未进行 OA 的文章。有人认为，这种“OA 优势”可能不是因果关系，而只是一种自我选择偏差，因为作者更倾向于将高质量的文章 OA。为了验证这一点，我们比较了有选择性的自我存档和强制性自我存档对 2002 年至 2006 年间在 1984 种期刊上发表的 27197 篇文章的样本。方法/主要发现：OA 优势在这两种情况下都同样显著。逻辑回归分析表明，这种优势独立于其他引文相关因素（文章年龄；期刊影响因子；作者人数、参考文献或页数；领域；文章类型；或国家），并且在最具引文影响力的文章中最高。OA 优势是真实的、独立的和因果关系的，但存在偏差。它的大小确实与质量相关，就像引文本身一样（前 20%的文章获得了大约 80%的所有引文）。结论/意义：OA 优势在更具可引性的文章中更大，不是因为作者在选择 OA 时存在质量偏见，而是因为用户在选择使用和引述时存在质量优势，OA 从选择性地仅向订阅者提供访问的限制中解放出来。希望这些发现将有助于推动大学、研究机构和研究资助者采用 OA 自我存档的规定。
