The Four: CC BY CC SA CC NC CC ND | Plus Two Combos: CC NC SA CC NC ND
CC BY: Attribution—Credit the creator, it's just good manners! Additionally, if it is a Creative Commons license, the BY element is mandatory and always attached to every other license. Even if you don't see the BY—it's there
CC SA: Share Alike—Use the same license, please
CC NC: Non-Commercial—Do not sell it, thanks.
CC ND: No Derivatives—Do not change or alter, got it?
CC NC SA: Don't use commercially and use the same license.
CC NC ND: Don't you dare use commercially and while we're at it, don't change it any way either.
Click on badges for complete details on each license:
The first copyright law we know of was the Statute of Anne, enacted in Great Britain in 1710. "The objective of the statute was to encourage the writing of "useful work" through granting authors the sole right to print their books for 14 years. (Bonner et al, 2). You can check out the full text on Yale Law School's Avalon Project website.
When the United States Constitution was written, the authors—obviously familiar with the Great Britain system of copyright—chose to include the following when enumerating the powers of Congress:
"To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries;" (U.S. Constitution, Article 1, Section 8)
This is the basis for our copyright law today, which lives in Title 17 of the U.S. Code.
In the United States, a work must be “fixed” in a tangible medium to breathe alive its copyright. While one can register a copyright to facilitate greater ability to seek damages for infringement, it is not necessary. Copyright is born with a work’s tangible manifestation automatically. This can take the form of:
Copyright does not protect facts, data, or ideas floating about in your head. Additionally, works of the U.S. federal government are generally not protected by copyright in the United States and are automatically in the public domain (17USC§ 105); however, there are numerous exceptions and refinements to this rule.
Copyright owners maintain the exclusive right to do the following:
These rights are exclusive to the copyright holder; no one else has these rights for someone else's content, unless the copyright holder gives them the right. Copyright lasts 70 years after the death of the copyright holder (all the many details and particularities about copyright term lengths can be found on Cornell University's Copyright Services: Copyright Term and the Public Domain LibGuide.
Or go straight to the source and read Copyright Law of the United States (Title 17).
Fair use is a legal exemption to the exclusive rights of copyright holders. It is determined on a case-by-case basis and is based on a consideration of the following four factors:
Because intention is a part of the consideration, only the user can make the initial assessment of whether their use is fair.
Columbia University has a good Fair Use Checklist that can help guide your determination on whether or not your use is Fair Use and therefore not protected by Copyright.
In short, public domain does not fit into copyright—public domain is its own kingdom and is not subject to copyright. Once something falls into the public domain it stays there. When copyright expires, (or was moved into the public domain by the owner, see below; or in cases where it never existed because it doesn't apply, see Fair Use, most government documents, facts, etc.; or was forfeited by failure to comply with formalities that may have preexisted current law) a work will move into the public domain making creative and intellectual works available for use. Different countries have different copyright laws which affects when things become a part of the public domain, but in the United States it is generally extended to 70 years after the life the creator. Yes, that's a long time to wait for the public good that public domain makes possible.
If you are using public domain materials you don't legally have to do anything, however, the clever folks at Creative Commons did make a public domain badge that you can use so that your readers know the status. It's a nice thing to do. And attribute when possible—there's no excuse for rudeness. Click badge for complete details.
But why wait 70 years? What if you want to put your work into the public domain now—just say to the world Have at it! Make cool stuff! Don't even worry about the details of who, what, where, or how—be free my friends! Well, the Creative Commons team thought of that too. They created a mechanism to dedicate your work to the public domain, copyright be damned. It's the CC Zero. But remember, attribution is always the polite thing to do. Click on badge for complete details.
Use of the CC Zero is restricted to the copyright holder, but if that's you, then go right ahead and share your stuff with no strings attach!
Governments provide most of the funding for research—hundreds of billions of dollars annually—and public institutions employ a large portion of all researchers.
Researchers publish their findings without the expectation of compensation. Unlike other authors, they hand their work over to publishers without payment, in the interest of advancing human knowledge.
Through the process of peer review, researchers review each other’s work for free.
Once published, those that contributed to the research (from taxpayers to the institutions that supported the research itself) have to pay again to access the findings. Though research is produced as a public good, it isn’t available to the public who paid for it. (read more at SPARC Open access)
How to Make Your Own Work Open Access: A step-by-step guide, out of the Harvard Open Access Project.
A Little History of Open Access and Open Educational Resources