We've all had great teachers who opened new worlds, maybe even changed our lives. What made them so great? Everyone agrees that a great teacher can have an enormous impact. Yet we still don't know what, precisely, makes a teacher great. Is it a matter of natural-born charisma? Or does exceptional teaching require something more? Building a Better Teacher introduces a new generation of educators, exploring the intricate science underlying their art. A former principal studies the country's star teachers and discovers a set of common techniques that help children pay attention. Two math teachers videotape a year of lessons and develop an approach that has nine-year-olds writing sophisticated mathematical proofs. A former high school teacher works with a top English instructor to pinpoint the key interactions a teacher must foster to initiate a rich classroom discussion. Through their stories, and the hilarious and heartbreaking theater that unfolds in the classroom every day, Elizabeth Green takes us on a journey into the heart of a profession that impacts every child in America.