Written by an esteemed scholar of second language acquisition with over 30 years of research and classroom experience, this book offers an in-depth analysis of Task-Based Language Teaching (TBLT) and the methods necessary to implement it in the language classroom successfully. The first part of the book combines a survey of theory and research in instructed second language acquisition (ISLA) with insights from language teaching and the philosophy of education. The second part details best practices for TBLT programs, from design to implementation and evaluation. It includes discussion of learner needs and means analysis; syllabus design; materials writing; choice of methodological principles and pedagogic procedures; criterion-referenced, task-based performance assessment; and program evaluation. A final chapter analyzes recent findings in the diffusion of innovation in education and assesses the potential impact of TBLT on second and foreign language learning. Innovative and forward-thinking, this is an exciting new approach to language teaching with important ideas for researchers and classroom practitioners alike.