The metaphors and operationalizations of quantification serve as an important lingua franca for much linguistic research, allowing methods and constructs to bring togeteher seemingly disparate areas of linguistic investigation. The studies in this volume illustrate forms of measurement and quantitative analysis that are current in diverse areas of linguistic research, from language assessment to language change, from generative linguistics to psycholinguistic experimentalism, from longitudinal studies to classroom research. The contributors demonstrate that quantification enhances the scientific study of language dialectically, through the rigor of explicitly operationalizing a construct, developing a reliable way to measure it, and finally validating that measurement. The range and clarity of the studies in the volume ensure that even linguists who would not traditionally use quantitative methods will find it useful. The many studies of language learning will be particularly helpful to language teachers.