A student organization decided to paint murals on the walls of the student union. You have a talented group of students who use the overhead projector to draw and paint the seven dwarfs from the Disney book, adding their own captions.
This figure is copyrighted and/or trademarked and is not able to be copied. This would also be considered creating a derivative work, which is illegal. Even if the characters are modified, as long as they are recognizable, it is a violation of copyright.
Analog vs. Digital Use
You want to teach swing dancing in your distance education class, so you've decided the best way is to include short segments from several different swing dancing videos. You found three such videos on amazon.com and purchased them. You also saw they were available in DVD, but you don't have a DVD player, so you got the videos instead. You plan to digitize these segments and load them on a streaming video server for students to view.
Until you found that the videos were also available in DVD format which is already digitized, you were probably OK. Short segments of an analog item may be digitized for distance education purposes if not available already in digital format and if available only to students in a particular class, protected by technological means such as a password. If they are already available in digital format, you cannot digitize them yourself.
Classroom Video vs. Streaming Video
After reading Victor Hugo's Les Miserables you have decided to have your distance education students watch the Liam Nee son video of the book via streaming video and compare it to the book. You do the same thing with your students in your on-campus section of the same class over several class periods. You borrow the video from your local Blockbuster to digitize it.
This is a dramatic work and falls under some additional copyright restrictions. You may only use "reasonable and limited portions of dramatic literary or musical works" - comparable to that which is typically displayed in the course of a live classroom session. This would not fit within the length requirements for either use or for digitization of an analog copy legally acquired.
Students learning multimedia creation decide to create an illustrated book. They scan in the pages of a short picture book and record themselves reading the text aloud on each page for a PowerPoint presentation.
This violates the brevity rule. You cannot copy an entire work, only limited sections of a work. Technically, only two pages of a picture book may be copies as long as those two pages do not comprise more than 10 percent of the text of the book.