There are four standards that you must consider when deciding whether fair use protects your use of a copyrighted work. You can use the acronym PANE to help you remember them:
Keep in mind that fair use is a subjective legal issue; that is, opinions may vary on whether your use of a copyrighted work is “fair.” Think of each of these guidelines on its own sliding scale, as in the image below (adapted from University of Minnesota Libraries, 2011):