 What is the main premise of OA?
Shifting from ink on paper to digital text suddenly allows us to make perfect copies of our work. Shifting from isolated computers to a globe-spanning network of connected computers suddenly allows us to share perfect copies of our work with a worldwide audience at essentially no cost. About thirty years ago this kind of free global sharing became something new under the sun. Digital technologies have created more than one revolution. I mean a group of authors defined by their topics, genres, purposes, incentives, and institutional circumstances, not by their wealth. Open access is the name of the revolutionary kind of access these authors, unencumbered by a motive of financial gain, are free to provide to their readers. Open access (OA) literature is digital, online, free of charge, and free of most copyright and licensing restrictions. In any case, we can be more specific about which access barriers OA removes. OA removes price barriers. As a result, users may be hampered in their research by barriers erected to serve intermediaries rather than authors. OA removes these permission barriers. These purposes include reading and searching, but also redistributing, translating, text mining, migrating to new media, long-term archiving, and innumerable new forms of research, analysis, and processing we haven’t yet imagined. OA makes work more useful in both ways, by making it available to more people who can put it to use, and by freeing those people to use and reuse it. In the jargon, OA delivered by journals is called gold OA , and OA delivered by repositories is called green OA . Work that is not open access, or that is available only for a price, is called toll access (TA). While every kind of OA removes price barriers, there are many different permission barriers we could remove if we wanted to. If we remove price barriers alone, we provide gratis OA , and if we remove at least some permission barriers as well, we provide libre OA . OA was defined in three influential public statements: the Budapest Open Access Initiative (February 2002), the Bethesda Statement on Open Access Publishing (June 2003), and the Berlin Declaration on Open Access to Knowledge in the Sciences and Humanities (October 2003). I sometimes refer to their overlap or common ground as the BBB definition of OA. Here’s how the Budapest statement defined OA: There are many degrees and kinds of wider and easier access to [research] literature.
 To make research literature available online without price barriers or without most permission barriers.
 To make research literature available online without price barriers or without most permission barriers.  To allow researchers to reuse literature for scholarly purposes.  To allow reproduction and distribution by readers.  To allow readers to write derivative works.