HandBrake is a free program that allows you to grab video from DVDs and save it as a file on your computer, saving you time in the classroom. In other words, instead of skipping around inside a DVD to find the relevant section, you can simply save the relevant portion as a file that can be played immediately. The program is available for Mac, Win and Linux, and the user manual is here. It’s pretty straightforward – put in the DVD, run HandBrake, choose specific chapters (or the whole DVD), and click Start. The end result is a digital video file saved to your computer.
Even though this kind of use is likely a Fair Use, it was formerly a violation of the DMCA’s anti-circumvention provisions. This changed in the latest exemption language, which states:
(1) Motion pictures on DVDs that are lawfully made and acquired and that are protected by the Content Scrambling System when circumvention is accomplished solely in order to accomplish the incorporation of short portions of motion pictures into new works for the purpose of criticism or comment, and where the person engaging in circumvention believes and has reasonable grounds for believing that circumvention is necessary to fulfill the purpose of the use in the following instances:
(i) Educational uses by college and university professors and by college and university film and media studies students;
(ii) Documentary filmmaking;
(iii) Noncommercial videos.
You can read the whole text here.
Note – I am not a lawyer, and whether or not something qualifies as a Fair Use is a decision made by judges in courts. That being said, fill out a Fair Use Checklist and keep it in a drawer somewhere, and you’ve probably done your due diligence. YMMV.