Open Access refers to unrestricted online access to articles published in scholarly publications. Types of open access publications available online include articles, books and book chapters, conference papers, theses, working papers, data and images.
There are three different ways of obtaining open accessibility to scientific research results:
Self-archive an open access version - Authors publish in the journal of their choice and archive or link to a freely available version of the manuscript in their institution's repository (UC Research Repository), or in a national repository (e.g. PubMed Central). A large percentage of publishers permit authors to archive a version of their article in an institutional repository.
Publish in an open access journal - Authors publish in Open Access journals that provide free and immediate access to the articles via the publishers web site. Authors may be required to pay an article processing charge.
Pay to publish open access in a traditional journal - a large percentage of subscription journals offer an Open Access publishing option, where articles can be made immediately available via open access. Authors are required to pay an article processing charge.
Introductory writings about open access by advocate Peter Suber