“Variationist Sociolinguistics: Change, Observation, Interpretation” is a comprehensive and authoritative survey of systematic variation in language, both present and past. The textbook, aimed at students taking intermediate and advanced courses in sociolinguistics, outlines the methodologies of research and data collection in the field, with explanations that go beyond the facts and into the philosophy of the field. The first real textbook of its kind, “Variationist Sociolinguistics” is an ambitious and exciting work that will be a must-have for students and researchers alike. Extra materials and answers to the exercises are available at www.wiley.com/go/tagliamonte