In the fall of 1995, one of us introduced a new technology that fundamentally changed the nature of large lecture classes: walkie-talkies. (1) This brief educational note describes the inspiration behind the walkie-talkie system, how it works, and the costs and benefits of using the system to teach large principles sections.
The idea for the walkie-talkie system resulted from giving my teaching assistant the opportunity to teach a large (200 student) class to help him gain experience teaching. Sitting in the back of the classroom to observe the teaching assistant provided an entirely different perspective on large classes! The students around me were very interested in what the assistant was teaching, and they constantly turned around to ask me questions. This experience shattered all of my preconceptions about students in the back of the room. They were not poor students, and they were not trying to hide from me. These students wanted to ask questions of the professor but were apparently afraid to shout them out in class. At that moment I decided that my class was not living up to its full potential because of the lack of participation from the students in the back, especially since more students sit in the back than up front.
A second and even more surprising observation was that most of the talking I heard in the rows around me was about economics. From the front of the class I had always wondered if the talking was about the class or about the student's social lives. Sitting in the back I heard students asking each other what was just said or asking someone else to explain the concept to them. This interaction between students is called "cooperative learning" and is often stressed by educators as an effective method of learning (see, for example, Majer and Keenan 1994).
I spent some time thinking about how to foster this kind of student interaction and also increase the class participation of the students in the back of the classroom. A primary consideration was that when students talked to each other, it carried two costs. First, the students who are talking miss the next thing the professor says. Second, others around them cannot hear. My idea was to have a kind of "pause" button where students could temporarily halt the lecture to interact with their neighbor. In this way they would not miss the next thing said, and other students would not be prevented from hearing my lecture. Immediately walkie-talkies, with their "beep" button, came to mind. When a student pressed the beep, I could stop for 30 seconds. This would allow pauses when they needed them. Also, walkie-talkies have a feature by which students can talk and have their question broadcast over the sound system in the class. I...