From Sources to Data: Medievalists, Demographers, and Computer Scientists Producing a Database from a Quattrocento Census (1964–1978)

Recent research in the discipline of history has explored the extent to which the datafication of historical sources has transformed the historian’s craft. Despite a significant body of knowledge, the crucial issue of the epistemological status of data is still overlooked in the discipline. Following recent research in data studies, this article claims that, in order to study the uses and accessibility of data, one should ask what led these data to serve as evidence in the first place. This article implements such an approach by analyzing the intellectual and material operations that led to the production of a database in an interdisciplinary collective between 1964 and 1978. I show how this raised major challenges for the historians who supervised the project. What practices and rules did they invent? What blueprint did they follow? And what is the epistemological status of the database they produced? I argue that these scholars invented a genuine approach to extracting data, in line with preexisting rules for editing historical sources. Criteria for future reuses of data outside their context of production are also examined.