This document summarizes research on using clicker technology in undergraduate education. It finds that clickers can increase student engagement and feedback, though gains in learning are small. The largest learning gains are for students with lower GPAs. Clickers allow for anonymity, immediate feedback, and more implementation options than previous methods. The document also describes a research study that found clicker use significantly increased student engagement over merely asking comprehension questions, though it took clicker users longer to respond to secondary stimuli. It concludes by outlining some challenges to using clickers, such as preparation time and technical issues.