Open access is more than free access
When people think about open access (OA), they immediately relate it with free access. And yes, free access is an important asset of open access publications. However, there is more to open access, which is especially worthwhile when you consider to publish open access yourself. According to the Open Definition “knowledge is open if anyone is free to access, use, modify, and share it”. So, providing reuse rights is another important asset of open access. A third feature of OA is that the author of an open access publication holds copyright on it instead of transferring all rights to the publisher.
Knowledge is open if anyone is free to access, use, modify, and share it
Keeping copyright on a publication means that you as an author can do anything with the publication without having to seek for permissions. You can republish it on a personal website, in a repository, such as Staff Publications, as a chapter in a PhD thesis, use it in a course and distribute it to all course members, or reuse and modify parts of it. However, when others want to reuse your paper, they need to ask your permission, except when you provided your publication with a Creative Commons license.
A Creative Commons license is a way to give permission for reuse in advance. They are commonly used in OA publishing. There are six different Creative Commons licenses: CC BY, CC BY-SA, CC BY-NC, CC BY-ND, CC BY-NC-SA, CC BY-NC-ND. The most open license is the license CC BY which allows the user to redistribute, to create derivatives, such as a translation, and even use the publication for commercial activities, provided that appropriate credit is given to the author and that the user indicates whether the publication has been changed. Another open license is CC BY-SA in which the letters SA (share alike) indicate that the derivative work should be shared under the same reuse rights, so with the same CC license. Adding the conditions only non-commercial use (NC) and/or no derivative works (ND) makes the Creative Commons licenses more restrictive and therewith less open.
A Creative Commons license is a way to give permission for reuse in advance
When you publish a paper as an Open Access publication, the publisher might use a standard CC licence (e.g. PLoS), or gives you a choice of three or more Creative Commons licenses (e.g. Wiley). If you have a choice, my advice would be to avoid any license with a non-commercial restriction in it, because in practice the term commercial turns about to be very vague and confusing. For scientific articles, I don’t see a reason for the clause No Derivatives, unless if you want to be notified and asked for permission when somebody intends to translate your paper. I am in favour of the most open license: CC BY, because it allows unrestricted use of the publication in all forms of education including MOOCs.
A truly Open Access article is an immediately free, online article with reuse rights. However, between open and closed access papers, a whole range of articles exist with different degrees of openness. If you want to know more I recommend the guide HowOpenIsIt? (PLoS/SPARC, 2014) for a concise overview of all the shades of open access.
Open Definition. Open definition 2.1. Retrieved from http://opendefinition.org/od/2.1/en
Creative Commons. Licenses and Examples. Retrieved from https://creativecommons.org/share-your-work/licensing-types-examples/licensing-examples/
Scholarly Publishing and Academic Resources Coalition, & Public Library of Science (2014). HowOpenIsIt? Retrieved from https://www.plos.org/files/HowOpenIsIt_English.pdf