Electronic-response systems (ERS) or audience-response systems (ARS) can be powerful instructional tools. Since the earliest adoption of ARS in the mid-1960s, the technology has changed significantly, especially in recent years, with advances in wireless communications. Over the years, ARS has become more sophisticated, more user-friendly, and cheaper. Typical ARS technology now allows instructors to present questions to the audience, and individual audience members respond with a keypad; responses are then automatically tabulated and displayed in a variety of graphic formats on-screen for feedback to the group. The tool is similar to that of the TV show “Who Wants to Be a Millionaire?” where every member of the audience transmits his or her response, and the distribution of responses is displayed on-screen.