This book takes a radically different look at communication, and in doing so presents a series of challenges to accepted views on language, on communication, on teaching and, above all, on learning. Drawing on extensive research in science classrooms, it presents a view of communication in which language is not necessarily communication - image, gesture, speech, writing, models, spatial and bodily codes. The action of students in learning is radically rethought: all participants in communication are seen as active transformers of the meaning resources around them, and this approach opens a new window on the processes of learning.