Learning by Expanding challenges traditional theories that consider learning a process of acquisition and reorganization of cognitive structures within the closed boundaries of specific tasks or problems. Yrjo Engestrom argues that this type of learning increasingly fails to meet the challenges of complex social change and fails to create novel artifacts and ways of life. In response, he presents an innovative theory of expansive learning activity, offering a foundation for understanding and designing learning as a transformation of human activities and organizations. The second edition of this seminal text features a substantive new introduction that illustrates the development and implementation of Engestrom's theory since its inception.