As a physics teacher, I often wonder how much my lecture is really helping students learn the subject matter. Do they understand what I am speaking to them about, or are they simply trying to copy down everything I say? When I finish discussing one topic, are they ready for the next? Am I getting my key points across to them during the lecture?
To answer these questions, I decided that I needed a quick, relatively unobtrusive method for obtaining student feedback right in the lecture environment. Although there are many ways of doing this during a lecture, including on paper quizzes, "raise your hand" surveys, flashcards, etc., I always find that quick and accurate evaluation of student responses is a difficult task. If I give a quiz in class, I must quickly shuffle through the papers, trying to get a sense of the students' answers. For "raise your hand" or flashcard type responses, I must quickly count hands and create a tally chart. Also, whenever asking students for feedback in class, I always have the usual problems of shyness and of students supporting only the answers they see most others in the class supporting. I wanted a quick way to survey the class on anything from a simple true-or-false question to a full textbook type of problem, right in the lecture.
On the ABC show "Who Wants to Be a Millionaire?" a contestant may ask the audience for help in answering a question. The contestant poses the question, and within seconds a histogram pops up on the screen, telling the contestant which answers (A, B, C, or D) the audience selected. This is exactly what I was looking for in my lectures: Ask the students a question and receive a quick tally of their answers to help me assess their comprehension and adjust my lecture accordingly.