In the fourth episode of the Idealized Science podcast, Dr. Beckey and Dr. Wargo discuss peer instruction -- a simple pedagogical technique that promotes classroom engagement and has been shown to lead to increased learning gains across scientific disciplines. We discuss implementing the technique, the paper entitled Why Peer Discussion Improves Student Performance on In-Class Concept Questions by Smith et al., and point the listener to a step-by-step guide entitled Peer Instruction: Engaging Students One-on-One, All at Once by Crouch et al.