Fair Use is a limitation on the exclusive rights of copyright holders (discussed in section 107 of Copyright Law) to help preserve First Amendment rights of free speech and promote conversation for purposes such as "criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research."
When evaluating whether a use is fair, four factors are taken into consideration:
No one factor is decisive - all four factors are considered.
Additionally, under factor 1, whether or not the use is transformative has become an important consideration for Fair Use evaluations. Here are three questions to ask yourself to help determine whether your use is transformative (from the Framework for Copyright Analysis tab):
Here are a few resources that go into Fair Use in more detail:
The only way to know for certain whether a use is fair is to defend a challenge in court. Fair Use is very context dependent, so only you can determine whether you believe fair use is applicable in your particular situation. However, there are a wealth of resources available to help you make an informed decision. Here are some checklists, guidelines, and best practices for a variety of situations. If you need further expertise, you can consult ASU's Office of General Counsel, or your own lawyer.