Students are more likely to honestly express their ideas—both scientifically valid conceptions and misconceptions—in a peer group where they have no fear than in front of a teacher who will be issuing grades. The Peer-Led Team Learning (PLTL) model emphasizes student achievement through active learning. Peer leaders play an indispensable role in keeping students on task, providing guidance, and using language that can easily be understood by students. PLTL is cooperative learning that really works.