Humming in the classroom

One of the challenges of teaching to large classes is to encourage the students to interact during the class. Today’s professors do not simply read their course to passive students. Most try to initiate interaction with the students by asking questions, polling the students opinions, ... However, my experience in asking questions to students in a large class shows that it is difficult to get answers from many students. Asking the students to raise their hands to vote for a binary question almost always results in : - a small fraction of the students vote for the correct answer - a (usually smaller) fraction of the students vote for the wrong answer - most of the students do not vote

One of the reasons why students do not vote is that they are unsure about their answer and do not want their colleagues or worse their professor to notice that they had the wrong answer. Unfortunately, this decreases the engagement of the students and after some time some of them do not even think about the questions that are asked.

To cope with those shy students, I’ve started to ask them to hum to answer some of my questions. Humming is a technique that is used by the IETF to evaluate consensus during a working group meeting. The IETF develops the specifications for most of the protocols that are used on the Internet. An IETF working group is responsible for a given protocol. IETF participants meet every quarter together. During these meetings, engineers and protocol experts discuss about the new protocol specifications being developed. From time to time, working group chairs need to evaluate whether the working group agrees with one proposal. This question can be discussed on the working group’s mailing list. Another possibility would be to use a show of hands during the meeting, but during a show of hands, it is possible to recognize who is in favor and who is against a given proposal. This is not always desirable. The IETF uses a nice trick to solve this problem. Instead of asking participants to raise their hands, working group chairmans ask participants to hum. If most of the participants in the room hum, the noise level is high and the vote is accepted. Otherwise, if the noise level is similar in favor and against a proposal, then there is no consensus and the proposal will need to be discussed at another meeting later.

Humming works well in the classroom as well when asking a binary question or a question having a small number of possible answers. Students can give their opinion without revealing it to the professor. Of course, electronic voting systems can be used to preserve the anonymity of students, but deploying these systems in large classes is more and costly and more time consuming than humming...