This article describes the author's experience in designing and implementing a student response system for a large lecture hall on a small budget. A Rutgers University physics professor describes an inexpensive, homemade electronic student response system designed for a large (330 seat) science lecture hall. Although limited, the system permits professors to interact with students and encourages students’ attention and participation. It works well for multiple-choice questions in both anonymous and tagged modes and for taking attendance and grading quizzes. Outcomes and plans for the future are also discussed.
