I don't know how most of you feel about 'cold calling' on students (calling on students who don't raise their hands). On the one hand, I want to respect students' desire to learn in their own ways and to engage the material in a fashion that's comfortable to them. I also don't want to students to feel intimidated or put on the spot, or worse yet, avoid coming to class for fear of having to speak. But on the other hand, cold calling creates the expectation that students need to be prepared for class, and in my experience, many reticent students actually have a great deal to contribute and can help their peers learn. Furthermore, students who don't speak in class aren't likely to get the help they need (they won't ask questions seeking clarification, for instance). And if you accept that the essence of philosophy is dialogue and shared inquiry, then isn't it reasonable to expect students to speak in class at least occasionally?
I've generally not cold called in the past, in large part because I didn't see a way to do it without seeming aggressive or making students feel cornered. The costs, I surmised, outweighed the benefits.
But here's a neat idea I came across that might diminish the anxiety associated with cold calling. Bring a pack of ordinary playing cards to class and deal each student one card. At appropriate moments, think of a card at random and ask for input from whoever holds the three of spades, the jack of diamonds, whatever you think of.
I like this because it makes it so that I'm not picking on a student (especially that I'm not picking on a student because the student tends not to speak in class). Since who gets selected is random, I might select a student who almost never speaks, but I might selective Mr. or Ms. Talkative. It also seems kind of fun and whimsical, so that the pressure is deflated a little bit. You could also make it a little 'safer' for those who are less likely to talk by taking their card once they've talked, so that they need not speak more than once.
I'd be interested to know people's reaction to this idea. My hope is that this would create an atmosphere where everyone feels more comfortable speaking and the expectation that speaking in class in normal, regardless of who you are.