Carol Aubrey's compelling book examines the nature and origins of subject knowledge. Her book is based on information gathered from observing the interactions between teachers and their first year pupils. Aubrey demonstrates the necessity of the classroom teacher to draw on many kinds of knowledge in order to deal with various issues surrounding classroom learning and teaching. Two important core areas are knowledge of lesson structure and of subject matter. It is the area of subject matter which this book addresses and, as such, it will be of primary interest to classroom teachers and lecturers in education, in addition to all those interested in primary education generally.