This comprehensive reference work provides an overview of the concepts, methodologies, and applications in computational linguistics and natural language processing (NLP). • Features contributions by the top researchers in the field, reflecting the work that is driving the discipline forward • Includes an introduction to the major theoretical issues in these fields, as well as the central engineering applications that the work has produced • Presents the major developments in an accessible way, explaining the close connection between scientific understanding of the computational properties of natural language and the creation of effective language technologies • Serves as an invaluable state-of-the-art reference source for computational linguists and software engineers developing NLP applications in industrial research and development labs of software companies