Many instructors are in a bind when it comes to class discussions: they want everyone in the class to contribute, but they do not feel comfortable calling on students who do not raise their hands to speak.
Kurtis Swope, in a 2006 article for the Teaching Professor, writes of an inspired technique to avoid this conundrum. He brings some many-sided dice (bought at a game store) to class, and whenever he asks the class a question, rolls the dice to determine which student is to answer. Swope notes that he still allows for open discussion in his classes, in which students freely respond to one another. But students quickly warm to the dice-rolling, Swope reports, adding that the technique "generates a sense of anticipation and attention because any student can be called upon at any time."
It's a good idea, not least because it involves those students who are too shy to raise a hand or otherwise unwilling to volunteer in class discussions without singling anyone out. By leaving the decision up to chance, the technique takes a part of class that students can be quite sensitive about and turns it into something that's truly democratic and maybe even a little exciting.
Source: Kurtis J. Swope, "Roll the Dice and Students Participate," in The Teaching Professor, April 2006, 20(4), 6.