This document discusses peer learning in online courses. It defines peer learning as students learning from each other without direct teacher intervention. The document outlines that peer learning has been shown to be effective both offline and online, as it allows for deeper discussions and scaling of online courses. It presents the Community of Inquiry framework and provides examples of how to structure peer learning through setting the online environment, modeling behaviors, assigning collaborative activities, and assessing student participation and engagement. Challenges with peer learning are also acknowledged around students perceiving peer feedback as less valuable and not being well trained in critique.