Fair Use
One of the most important limitations to copyright is the doctrine of “fair use.” There is no formula to ensure that a predetermined percentage or amount of a work (specific number of words, lines, pages, or copies) may be used without permission. Rather, determining whether the fair use privilege applies in any given situation requires consideration of the factors below.
- The purpose and character of the use. Does the new work serve as a substitute for the original or instead add something new, with a further purpose or different character—i.e., is it transformative?
- The nature of the copyrighted work. Is the material being used factual or is it creative? The former is more likely to be considered fair use than is reuse of creative content such as a poem, play, or song.
- The amount and substantiality of the portion used. The more material you take, the more likely it is that your work will serve as a substitute for the original work, adversely affecting the value of the copyright owner’s work. There is no absolute limit for fair use. It all depends on the circumstances. How much of the whole are you using? Do the brief excerpts that you are reproducing represent the “heart of the work”?
- The effect of the use upon the market of the copyrighted work. Will your use adversely and substantially impact the potential market for the original work?
For more on fair use, visit Stanford University Copyright & Fair Use Project, or Columbia University Fair Use Checklist.
Public Domain
A work of authorship is in the “public domain” if it is no longer under copyright protection or if it failed to meet the requirements for copyright protection. Works in the public domain may be used freely without the permission of the former copyright owner.
Public domain texts include any text first published in the United States before January 1, 1923, and anything first published in the United States before January 1, 1964, for which copyright was not renewed. All works of the US government of whatever type or medium are also in the public domain. (State government documents or documents of foreign governments may be protected by copyright, however.) Publications and photographs in the possession of the US government (i.e., from the Library of Congress and National Archives) may or may not be in the public domain.
Although you need not request permission to use material from public domain works, you should give full credit to the source. For more on Public Domain, visit the Cornell University Copyright Information Center or the Stanford University Copyright & Fair Use Project.