Book excerpt: "While many of us assume that experience makes teachers better at their jobs, remarkably little research has been done to understand how teachers develop expertise and how it affects their teaching. In Teaching Expertise in Three Countries, Akiko Hayashi gives us a remarkable look at the careers of teachers over the course of more than fifteen years. Not only does her research cover a remarkable timespan, it also studies teachers from three national contexts: Japan, China, and the United States. Hayashi builds on the research that began with Joseph Tobin et al.'s celebrated 1991 book Preschool in Three Cultures, examining six teachers profiled in Tobin's 2009 follow up Preschool in Three Cultures Revisited. Hayashi showed those six teachers videos shot in their classrooms twelve years earlier and asked them to reflect on how they have changed. She also interviewed 120 experienced childhood educators from China, Japan, and the US. The teachers' analysis of changes in teaching style and even the way they talked about their trajectory from novice to expert uncovered important cultural differences. While Japanese teachers described experienced educators as less "in their own heads," Chinese teachers said they took command of a classroom. And American teachers with experience reportedly knew when to let things go. Across the three cultures, experienced teachers also had remarkably similar things to say about their approach to teaching. Experienced teachers in all three cultures describe themselves as being quieter, knowing children better, being more "present" and "in the moment," and having better judgment about which incidents require their intervention. All the same, they followed different professional trajectories. While Chinese educators embraced new ideas and the younger educators that brought those ideas into the classroom, Japanese educators valued traditional methods. US educators were encouraged to adopt new research in their teaching practices, but the new ideas required them to follow rules and scripts, limiting their ability to make use of years of experience. Teaching Expertise in Three Countries helps us see how experience forms teachers, despite national differences, and how we can best support them to make use of their incredible knowledge"--