Learning and teaching complex cultural knowledge calls for meaningful participation in different kinds of symbolic practices, which in turn are supported by a wide range of external representations, as gestures, oral language, graphic representations, writing and many other systems designed to account for properties and relations on some 2- or 3-dimensional objects. Children start their apprenticeship of these symbolic practices very early in life. But being able to understand and use them in fluid and flexible ways poses serious challenges for learners and teachers across educational levels, from kindergarten to university. This book is intended as a step in the path towards a better understanding of the dynamic relations between different symbolic practices and the acquisition of knowledge in various learning domains, settings and levels. Researchers from almost twenty institutions in three different continents present first hand research in this emerging area of study and reflect on the particular ways and processes whereby participation in symbolic practices based on a diversity of external representations promotes learning in specific fields of knowledge. The book will be useful for persons interested in education, as well as cognitive psychologists, linguists and those concerned by the generation, appropriation, transmission and communication of knowledge.