Understanding vocabulary and its role in language learning is one of the central tasks of applied linguistic research. It is also an area that has seen, and continues to see, huge progress in terms of the complexity and diversity of work being done. While this makes for a rich and exciting research scene, it can also make the task of developing vocabulary research skills a daunting one as specialist subfields develop ever more sophisticated concepts and methods. This book aims to give readers an understanding of the area that is both detailed and rounded by introducing them to understanding and doing vocabulary research from four key perspectives: corpus linguistics, psycholinguistics, language testing, and teaching and learning. Within each area, a state-of-the-art review describes fundamental concepts and commonly used methods, evaluates ongoing methodological debates, and points to areas for future development. It aims both to give readers a solid grounding in the specialized methods and debates associated with each area and to build connections across these specializations, considering points of contact and ways in which they can work together.