Measured Language: Quantitative Studies of Acquisition, Assessment, and Variation focuses on ways in which various aspects of language can be quantified and how measurement informs and advances our understanding of language. The metaphors and operationalizations of quantification serve as an important lingua franca for seemingly disparate areas of linguistic research, allowing methods and constructs to be translated from one area of linguistic investigation to another. Measured Language includes forms of measurement and quantitative analysis current in diverse areas of linguistic research from language assessment to language change, from generative linguistics to experimental psycholinguistics, and from longitudinal studies to classroom research. Contributors demonstrate how to operationalize a construct, develop a reliable way to measure it, and finally validate that measurement -- and share the relevance of their perspectives and findings to other areas of linguistic inquiry. The range and clarity of the research collected here ensures that even linguists who would not traditionally use quantitative methods will find this volume useful.