By Karen Grigg, Associate Director of Collection Services at the Duke Medical Center Library:
Open Access comes in a variety of flavors. The two main types of open access are that of open access journals and self-archiving methods
Open Access journals are those that are freely available to the end-user. Since the reader does not pay for content, costs must be subsidized by the author or the institution. Along with publication fees, submission fees are sometimes charged.
Examples:
BioMed Central, an online publisher of free peer-reviewed scientific articles, is sustained by revenue from institutions. However, the new “Shared Support Membership” allows institutions and authors to share article costs.
Public Library of Science, or PloS, charges a publication fee that can be paid by the author or the author’s employer. PLoS also relies on donations from foundations.
Self-archiving allows authors to submit their own material online so that it is accessible to the public. There are two main varieties of self archiving; institutional repositories (IR), and Subject Based Repositories. IR are hosted by an institution, such as a university, and bundles all the research output of the institution. Often, the work is done by librarians or IT staff. One such IR is eScholarship from the University of California. A subject-based repository is hosted independently of an individual institution, and bundles the research output of a subject of discipline. Authors voluntarily self-archive their work on a pre-print server. An example of a subject repository is Arxiv, a repository for- physicists and mathematicians. Finally, authors often post articles on their own web sites, but the ability to do so requires negotiation with the publisher.
There are also some hybrid models of open access. Some publishers allow authors to decide whether or not an article can be openly accessed. Authors who would like their article to be freely available can opt to pay the publishing fee. These fees can be several thousand dollars per article. The Delayed OA model gives public access to journal articles after an embargoed period, often 6 months to 1 year. With a Partial OA journal, certain parts of the journal; often editorials or abstracts, are freely available, while the bulk of the content is for fee. Finally, Retrospective OA allows access to older journal articles that have been digitized.
For more background on Open Access Models, see:
Zhang, Sha Li. “OCLC Systems & Services | The Flavors of Open Access.” OCLC Systems & Services 23.3 (2007): 229-34. Emerald. Web. 15 Sept. 2010. <http://www.emeraldinsight.com/journals.htm?articleid=1622087&show=html>.
“Peter Suber, Open Access Overview (definition, Introduction).” Earlham College — Richmond, Indiana. Web. 15 Sept. 2010. <http://www.earlham.edu/~peters/fos/overview.htm>.