Free and Open Access Resources

What are "Open Access" and "freely available" resources, and why do I need them?  

These terms refer to information that has been made freely available to the public, such as research articles, data, images, works of fiction, and many more.  "Open access" and "free" are not synonymous.  Varying copyright restrictions are one reason for the difference.  For example, all articles accessed via PubMed Central are free, but only approximately half are labeled "open access."  

What is the PMC Open Access subset? Isn't everything in PMC open access?

The majority of the articles in PMC are subject to traditional copyright restrictions. They are free to access, but they are not Open Access articles in the specialized sense of that term.  The PMC Open Access Subset contains articles that are still protected by copyright, but are made available under a Creative Commons or similar license that generally allows more liberal redistribution and reuse than a traditional copyrighted work. 

Example:  say you need a photo of a man for a report you're writing.  You can look at many images online for free. But you cannot use an image without checking copyright restrictions. 

Other terms

"Open archive" is often seen as well.  As Elsevier uses these terms, "open access" means an article is free to access as soon as it is published. "Open archive" means an article is published in a journal that makes articles available for free after some embargo period (not immediately when it is published).

Many major funding institutions now require Open Access, including:

NIH (National Institutes of Health) policy on NIH-funded research

"The NIH Public Access Policy implements Division F Section 217 of PL 111-8 (Omnibus Appropriations Act, 2009).  The law states:  The Director of the National Institutes of Health ("NIH") shall require in the current fiscal year and thereafter that all investigators funded by the NIH submit or have submitted for them to the National Library of Medicine's PubMed Central an electronic version of their final, peer-reviewed manuscripts upon acceptance for publication, to be made publicly available no later than 12 months after the official date of publication: Provided, that the NIH shall implement the public access policy in a manner consistent with copyright law."   https://publicaccess.nih.gov/policy.htm

Bill & Melinda Gates Foundation's policy

"The Bill & Melinda Gates Foundation is committed to information sharing and transparency. We believe that published research resulting from our funding should be promptly and broadly disseminated. We have adopted an Open Access policy that enables the unrestricted access and reuse of all peer-reviewed published research funded, in whole or in part, by the foundation, including any underlying data sets."  http://www.gatesfoundation.org/How-We-Work/General-Information/Open-Access-Policy

Many databases offer no-charge searching and citation retrieval; that is, an article's basic information, including author, publisher, article title, and sometimes the abstract as well.  Retrieving full-text is different, as full texts are often still locked by the publishers: in order to read the full text, one would need either an institutional subscription or pay-per-view.

Such an access model is inconvenient to the researchers and the global scholarly community. In recognition of such a problem, a number of initiatives began to promote open access to the scientific literature. For instance, the Budapest Open Access Initiative reaffirmed in its 10th anniversary in 2012 that its goal is to make open access the default method for distributing new peer-reviewed research in every field and country. Agreed with such initiatives, a number of publishers and journals are adopting the open access paradigm for publishing articles. For instance, two major open access publishers include the BioMed Central (BMC) and Public Library of Science (PLoS). To accelerate open access, the U.S. National Library of Medicine started PubMed Central (PMC), a free digital repository of full-text articles in biomedical and life sciences in early 2000.    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4593617/