Remember the intent of copyright:
"to promote the progress of science and the useful arts"Authors are given a mini-monopoly to reproduce, distribute, adapt, perform and display their work, as an incentive to encourage development of new work.
If this mini-monopoly would interfere with the "general" production of more new work, however, limitations will be placed upon it.
gives scholars, researchers, authors, etc., permission to make limited use of the work of another without asking permission.
To determine whether your intended use falls under the Fair Use principle, consider all four of these issues:
If the work is "transformative" then fair use is more likely to be applicable.
Typical acceptable transformations include:
Fair use is more likely to apply in the above situations if the use of the otherwise protected work in the situation is intended to advance new knowledge. It is less likely to apply if the intention is simple commercial gain.
Fair use is more likely to apply if the original is a factual work (e.g., scientific or technical paper) than a work of fancy (e.g., novel or poem).
For example, there are only so many ways to state a physical law. Since the principle itself is not covered by copyright, and there are a limited number of ways to express it completely and accurately, many such expressions may be fairly used by others.
Fair use as applied to unpublished materials is a very complicated topic. An extreme oversimplification is that a major limitation to its fair use involves any potential negative impact on the later value of publishing the original.
Fair use does not mean that you can automatically re-use out-of-print work, but it does suggest that less-strict guidelines are applicable when a previously-published work is no longer readily available through normal means.
The larger the amount, and proportion, of original expression you want to use, the less likely it is covered by fair use.
The more important the specifics are to the original work, the less likely it is covered by fair use.
The more your use is likely to have a negative impact on the potential market for, or value of, the original or derivative works of the original, the less likely your use is covered by fair use.
The more that similar copying by others would further reduce the value of the original or derivative works, the less likely your use is covered by fair use.
In a legal distpute, as the copier it will be up to you to show that your use did no harm to the value of the original. Unless your intended use meets all four criteria for fair use, then you must get the copyright holder's permission before you can use protected material.
Note that educational use is not automatically covered by fair use.