I let students know that I often start classes with easy questions about the previous day, which allows quieter, well-prepared students the option to get something out at the start when others are still shuffling papers and the focus on the speakers is diminished. Once they talk a little, though, even if it's because they feel they have to, it seems to open a door a crack for more comments during the meatier discussions.
Doug Lemov, in a Guardian article, agrees:
"...teachers need to maximise the amount of thinking and learning going on in their classroom at any one time, and to ensure that this effort is widely distributed. Take “cold calling”. Instead of asking a question of the class and then picking a hand, you call on a student regardless of whether they have raised their hand. It sounds too simple to be significant. But, to use one of Lemov’s favourite phrases, cold calling is “a small change that cascades.” Cold calling enables the teacher to check on the level of learning of any student in the class; it keeps the pace of the lesson high, because the teacher no longer has to wait for volunteers; it makes the teacher look more authoritative. Crucially, it increases the amount of thinking going on in the classroom at any one time because everyone knows the next question might be for them."As a student, I had an Animal Learning prof who did a daily once-around with a different question for each student. It was nerve-wracking, but I learned the content of the course effortlessly. We couldn't not pay attention. In terms of effective teaching, it worked. In another class, a well-meaning, young prof lectured without demanding much student response. We could relax and were free to zone out at will. Then a guest-speaker came in for a class, and she made sure she heard every student speak once. It's the only lesson I remember. I can't even picture the original prof's face.
However, in his most recent post, Alfie Kohn refers to these tactics as "bullying." He suggest that the practice,
"...is so fundamentally disrespectful of students that I'd be disinclined to take advice about anything from someone who endorsed it. . . . a teacher is basically saying, 'It appears you'd rather not contribute to the discussion right now, but I don't care about your preference and I'll use my power to force you to contribute.' If this isn't disrespectful, then that word has no meaning. . . . The goal is to produce a certain observable behavior; the experience of the student - his or her inner life - is irrelevant."He recognizes the problems with 20% of the class talking and the remainder silent, but maintains that the right to refuse to participate is paramount. And then he ends his essay with an odd hope that we'll all learn to use "self-governing conversation" in which no student feels the need to raise their hands, but they take turns without being mediated.
I'm not convinced students talking without raising hands is in any way preferable to having a monitor of some sort choose hands roughly in the order they were raised or in a way that allows all voices to be heard. It feels friendlier without, but even among friends, if there are enough of us in a room having a heated debate, we'll start raising out hands because it's a useful way to make sure we're all heard. I generally am the "caller of names" during discussions, but students are quick to let me know if I've missed someone's hand. They have a keen sense of equity. Raising hands makes the conversation faster and more equitable with an attentive monitor who ensures nobody dominates.
But I also want to address an underlying premise in Kohn's piece, that being uncomfortable or anxious in class is necessarily a bad thing - or a brutal thing by his estimation. Allowing shy students to avoid ever speaking in class reinforces their fear of speaking in front of people. It seems nice in the short term, but in the long run they're accommodated to their own detriment. Like playing piano and learning multiplication table, sometimes we have to be made to do things we don't want to do, but it does get easier the more we actually do it.