Changes in society are inevitably reflected inchanges in education and especially in schoolcurricula. However change has also been acknowledgedas difficult and one area where change is fiercelycontested is in school curricula. Mandated change isoften resisted and can be diverted from its originalcourse.This book looks at the wide scenario of mandatedcurriculum change in the context of a specificsubject. The development of a new physics curriculumand its implementation in schools are explored usingin-depth interviews with the writers of thecurriculum and teachers who were involved in theimplementation.The rich experiential data is analysed using asociocultural theoretical framework especially thatof Etienne Wenger. Three key elements are identifiedas being critical to effecting any real change. Amodel of curriculum change based on the concepts ofreification and dereification is developed.The descriptions, analyses, and theory in this bookwill be of value to education policy makers,curriculum developers, teacher educators and teachersthemselves as they set out to make real changes inthe classroom and not just on paper.