Copyright law protects "original works of authorship fixed in a tangible medium of expression" for a limited period (17 U.S.C. §102). Copyrights are conveyed an individual(s) as soon as their work is fixed; formal registration is not required. U.S. copyright law (17 U.S.C.) applies to traditional media (books, records, etc.) and digital media (electronic journals, Web sites, etc.).
Copyright protects the following eight categories of works (17 U.S.C. §102):
A copyright holder receives six exclusive rights (17 U.S.C. §106):
Copyright does not protect:
Copyrights cannot be held in perpetuity. The United States Constitution (U.S. Const. Art. I, §8) states that "The Congress shall have Power ... to protect 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." However, copyright protection does last a long time. See this table to understand more fully the complexities of copyright duration.
Keep in mind that, since 1989, a copyright notice has not been required to be displayed on an item; works that meet basic copyright requirements--an original work of authorship fixed in some form--are automatically protected by law. The copyright holder may add a copyright notice to their work to clarify to users who owns the content.
Fortunately, copyright law incorporates several exceptions that limit a copyright holder's six exclusive rights. For educational purposes, the most important exceptions are:
An important exception in the Copyright Act is the Fair Use Doctrine (17 U.S.C. §107). Fair use permits users, under certain circumstances, to copy, distribute, adapt, publicly perform, or publicly display portions or all of a copyrighted work without the copyright holder's permission. To evaluate whether you believe your use is a fair use, the following four factors must be addressed:
Use the Fair Use Evaluator for step-by-step guidance in making a fair use decision, and/or contact library consultants for assistance. Print out a copy of your evaluation to keep for your record as evidence of your decision-making process. Remember, fair use is used as a defense in a court of law; only a court can determine whether your use is deemed a fair use.
The University of Minnesota Libraries has developed a useful "Thinking Through Fair Use" tool that guides users through a fair use analysis.
A work is in the public domain when its copyright term has expired or a copyright holder chooses to relinquish their rights and place the work in the public domain. Materials produced by federal government employees are in the public domain. Materials created by state employees may or may not be protected, depending on that state's legislation.
Peter Hirtle of Cornell University created the following useful chart, updated annually, that describes the intricacies of copyright duration: