This book focuses on the talk of science classrooms and in particular on the ways in which the different kinds of interactions between teachers and students contribute to meaning making and learning. Central to the text is a new analytical framework for characterising the key features of the talk of school science classrooms. This framework is based on sociocultural principles and links the work of theorists such as Vygotsky and Bakhtin to the day-to-day interactions of contemporary science classrooms.