One of the ideas that seems the easiest to implement and the most practical is varying the hand signals. I went into this a little bit in one of my previous posts. But, Rick Morris' seminar went into greater detail.
And now, you have an easy way to classify how a student will participate before they actually participate. On top of that, getting students to use signals such as these forces students to think about how they will participate before they do so. Also, if you are trying to save time such as by avoiding comments that may take the lesson off track, then you can avoid hands that are showing that signal.
Unfortunately, the picture turned out blurry, so I'll have to describe the hand signals to you. If a student uses sign language for "A," that means that they have an answer. It is a closed fist pointing up with the bottom of the thumb pressed against the index finger.
If a student uses sign language for "I," it means that they have a question. It is a closed fist except the pinky finger is pointed up.
If a student uses sign language for "C," that means that they have a comment. Simply make a C shape with your hand.
If a student crosses their middle and index finger, that means that they want to use the restroom.
If a teacher merely holds up an index finger, they are indicating to a student to wait a moment.
If a teacher or student holds up an open hand as though saying "stop," it means that the student is saying something off topic.
If a teacher holds up a peace sign (i.e. making a V shape with his/her middle and index finger), the teacher is asking for a volunteer.
If a teacher sticks one hand straight out with the palm facing up and has the other hand standing on it with the middle and index finger, the teacher is telling students to stand up.
If a teacher has the middle and index finger of one hand sticking out and the same fingers of the other hand making a falling motion on that first hand, the teacher is signaling to a student to sit down.
A student who sticks only their index, middle, ring fingers up with the remaining fingers closed, and motions back and forth towards their mouth is signaling that they want water.
A student or teacher who puts their arm at a 45 degree angle with the hand of that arm open and point up is signaling that they are ignoring a student.
A teacher who crosses their hands in front of their chest, uncrosses them, and makes a sliding motion with their hands as though wiping a desk is signaling students to put writing utensils down.
Finally, a teacher or student who puts their open hand on their mouth and motions it to point it at someone is signaling thanks to someone.
Ok. Hopefully, you'll be able to make sense out of some of those descriptions.