So I started trying something today and I really like it. That's why I'm passing it on to you. When I call on a student and they say, "I don't know", they have the option of phoning a friend. It's not a new concept, but I added a slight yet significant twist. When they 'phone a friend', they have to re-ask the question in their own words. Meaning, they have to articulate exactly what it is that they don't know.
It proved to be extremely difficult for some of my students. Possibly because their answer of "I don't know" was just a cover for not having paid attention. But it was even difficult for a couple of students whom I know were paying attention, they just couldn't pinpoint what exactly they didn't understand.
It's quick and it's simple, but I like it and I think it will help me know my students better and it will help teach them to independently monitor what exactly is confusing them. Oh yeah, they also find it fun to use the whisper phones to call each other with.