At this point, clickers and other electronic tools that encourage student interaction are accepted instructional practices and commonly used in large courses. What they offer that other instructional strategies don’t is a means for every student to participate. Their effects are also relatively easy to study, and consequently, there’s a plethora of research that explores how they affect learning. As we have come to expect with empirical analyses of instructional approaches, the effects are mixed: some results report learning gains and others don’t.