This book aims at scaffolding language teachers, pre-service language teachers, and undergraduate students in the process of teaching and material design by helping them to become informed decision-makers in this endeavour. It also aims at leading foreign language teachers to reflect critically on some key concerns in our field as well as on their own beliefs, and to act consistently with that critical reflection to introduce, little by little, changes in daily practices that can ultimately transform students' thinking. On this book, the authors discuss relevant elements related to curriculum, principles that have guided some educational philosophies, systems of beliefs, psychological theories of learning, principles for material design, and the influence of the development of computers, computer science, and Information and Communication Technologies (ict).