Book excerpt: This book provides interdisciplinary perspectives on task-based language teaching (TBLT) and task-based language assessment (TBLA) in English as a second language (ESL) context. It discusses theoretical and experimental insights of TBLT and TBLA from cognitive, cognitive linguistic, and psycholinguistic viewpoints. The chapters, written by leading language teaching specialists in the field, introduce the reader to a comprehensive range of issues related to TBLT and TBLA such as curriculum design, materials development, and classroom teaching & testing. With interdisciplinary appeal, the book is a valuable resource for researchers in task-based language teaching and assessment. It is equally useful for teachers to whom it offers practical suggestions for designing tasks for teaching and testing.