Fair use allows for the unlicensed use of copyright-protected works in certain circumstances, including "criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research," according to Section 107 of the Copyright Act. Four factors must be considered in determining whether a use of copyright-protected material is fair:
All four factors are important, though the first and fourth factors are often the ones most considered in court cases. Typically, educational uses are favored over commercial uses of works for fair use, and creative works are more protected by copyright than factual works. There is no specific rule of thumb for determining an amount of the work that is "fair" to use; it is important to consider what constitutes the "heart" of a work.
While there are no hard-and-fast rules to determine fair use, there are some excellent checklists that can be used to help determine fair use, including the Cornell Copyright Information Checklist and the Columbia University Libraries Fair Use Checklist.
Fair use applies to both published and unpublished works.
Courts weigh all four factors in determining fair use. However, they are most likely to find that a use was fair when they find a transformative purpose. According to Copyright for Educators & Librarians, transformative use is found when a new meaning is created or a new purpose pursued.
Key questions to ask to see if a use is transformative are:
As an example of transformative fair use, in the Authors Guild v. HathiTrust lawsuit, the Court found that it was fair use to digitize copyrighted works, as digitization made them searchable and indexable in new ways; allowed for preservation; and provided access to people with print disabilities.