Kemi Amin
Kemi Amin
Kemi is the Communications Manager for the UCSF Library.

Four Factors of Fair Use – Third Factor: Amount and Substantiality of the Portion Taken

The third factor of fair use concerns itself with the amount of material used from a particular work. Have you used only what you need to achieve your purpose? Can you achieve your purpose without it, or with less? Is what you are using “the heart of the work?”

Courts do not set limits on quantity. There is no maximum; even the use of an entire work can be fair, particularly if the use is transformative. And there is no minimum; using a small portion may not be fair under certain circumstances. However, generally, the more you use, the more likely the use will be determined as not a fair use. Courts have also ruled against fair use when a small amount was used but was determined to be “the heart of the work.” An example of this could be a small section of a magazine article, but which contained the “scoop.” Another example could be a film clip that contained the most creative expression of the film. The courts have ruled in favor of fair use when works are transformative (parody, criticism, commentary) even with large amounts of a work used. In non-transformative cases, the courts are more concerned with whether your use might affect the market for the work.

Come see us! The Library will be hosting a table today in the lobby of the Medical Sciences Building from 12:00-1:00pm, and in the lobby of the Parnassus Library from 1:30-2:30pm. Stop by, learn about fair use, ask any copyright questions, and grab a snack to go!

Check out these LibGuides for more information on copyright, fair use, and finding and using images:


Visit the UCSF Library Fair
Use Pop-up Table:
Thursday, February 23
Medical Sciences Building Lobby | 12 – 1 pm
Parnassus Library | 1:30 – 2:30 pm

Contact Peggy Tahir, Education & Copyright Librarian.