In recent years, scholarly research in a range of fields, including media studies, has capitalised on the availability of ever-increasing numbers of data, generated by corporations, public administrations and other organizations. However, the collection, selection and analysis of so-called ‘big data’ is not a new phenomenon. This issue of TMG – Journal for Media History takes a media historical perspective on datafication, and on the analysis of data in different areas of cultural, social and economic life. It also contains articles that zoom in on antecedents of current practices of (big) data analysis in media studies specifically, and interviews with media scholars on the data and data practices they research, or the methodologies they develop for the purpose. The issue was edited by Karin van Es and Eef Masson.