This volume makes a unique contribution to the literature on materials development for language learning. It focuses on issues related to authenticity in materials development and includes research-based position statements, applications of theory to practice and developments of theory from observed practice. Each paper concentrates on a different aspect of authenticity and many of them introduce the reader to previously unexplored facets of authenticity. The chapters are sequenced so that the book moves from general discussion about the value of authenticity to reports of evaluations of authenticity to reports of the exploitation of authenticity in specific learning contexts. Many questions are raised, much revealing data is reported and analysed, and many pedagogic suggestions are made. The contributions here have been written so that they are of potential value to teachers, to materials developers, to post-graduate students and to researchers. They are written to be academically rigorous, but at the same time to be accessible to newcomers to the field and to experienced experts alike.