This volume aims to overcome sub-disciplinary boundaries in the study of linguistic variation - be it language-internal or cross-linguistic. Even though dialectologists, register analysts, typologists, and quantitative linguists all deal with linguistic variation, there is astonishingly little interaction across these fields. But the fourteen contributions in this volume show that these subdisciplines actually share many interests and methodological concerns in common. The chapters specifically converge in the following ways: First, they all seek to explore linguistic variation, within or across languages. Second, they are based on usage data, that is, on corpora of (more or less) authentic text or speech of different languages or language varieties. Third, all chapters are concerned with the joint analysis (also sometimes known as "aggregation" or "data synthesis") of multiple phenomena, features, or measurements of some sort. And lastly, the contributors all marshal quantitative analysis techniques to analyse the data. In short, the volume explores the text-feature-aggregation pipeline in variation studies, demonstrating that there is much mutual inspiration to be had by thinking outside the disciplinary box.