During student-centered learning activities, students actively engage in their own learning based on individual prior understandings. It can be difficult for a teacher to know if students fully understand the concepts being presented, especially if they do not comment or ask questions because they are shy or afraid of getting something wrong. Teachers may not know students’ true ideas until they express themselves on a written summative exam, and then it is often too late to correct them before rushing off to the next topic. Therefore, the author uses pretests, daily learning logs, and posttests to assess student learning and change misconceptions. She shares her strategy in this month's Idea Bank.