Dave Berque, a computer science professor at DePauw University in Greencastle, Ind., got an odd wake-up call years ago when he was teaching a large class at an East Coast institution. He tried to get the class involved in the lesson; he tried asking questions; he tried urging them to ask questions. For the first four weeks, no interaction from students.
Then, one day in the fifth week, he had five or six people raise their hands. Unfortunately, it was not to ask questions, but to tell him the ceiling lights had caught fire.