In 1991 Allan Collins, John Seely Brown and Ann Holum published 'Cognitive Apprenticeship: Making Thinking Visible'. Nearly a quarter of a century later John Tomsett encountered their paper and since then, it has influenced his teaching immeasurably. Collins et al. believed that 'domain (subject) knowledge ... provides insufficient clues for many students about how to actually go about solving problems and carrying out tasks in a domain'. They believed that you had to make expert subject thinking visible to students. Consequently, Tomsett developed a number of techniques which made his expert subject thinking visible to his students, to great effect. Beyond his own practice, the principles behind Collins et al's paper have been woven throughout Huntington School in York, where Tomsett is headteacher, a research school whose teachers are committed to developing evidence-informed classroom practice. In this book, the latest in the 'In Action' series, a number of Huntington School teachers discuss what they consider to be the expert thought processes specific to their individual subject domains. They explain in detail how they use cognitive apprenticeship techniques 'in action' to make their disciplinary thinking visible and help their students learn those same expert thought processes. This book is a priceless contribution to the current debate about the curriculum and how it is taught in our schools.