Green open access

Self-archiving is the act of (the author's) depositing a free copy of an electronic document online in order to provide open access to it. The term usually refers to the self-archiving of peer-reviewed research journal and conference articles, as well as theses and book chapters, deposited in the author's own institutional repository or open archive for the purpose of maximizing its accessibility, usage and citation impact. The term green open access has become common in recent years, distinguishing this approach from gold open access, where the journal itself makes the articles publicly available without charge to the reader.

Self-archiving was first explicitly proposed as a universal practice by Stevan Harnad in his 1994 online posting "Subversive Proposal" (later published in Association of Research Libraries) although computer scientists had been practicing self-archiving in anonymous archives since at least the 1980s (see CiteSeer) and physicists had been doing it since the early 1990s on the web (see arXiv).

As of September 2015, 78% of the 2107 publishers registered in the SHERPA/RoMEO publisher policy index endorse self-archiving by authors of the preprint and/or postprint versions of their papers.

A majority of journals endorse unembargoed self-archiving of the postprint, immediately upon acceptance for publication. Other journals impose an embargo of 6–12 months or more on making the article open access.

Some publishers, such as Cambridge University Press or the American Geophysical Union, endorse self-archiving of the final published version of the article, not just peer-reviewed final drafts.

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