Cal Biruk is Professor of Anthropology at Oberlin College and Conservatory. Their research focuses how data reflect and cohere new social relations, persons, forms of expertise, and exclusions in sub-Saharan Africa. Their forthcoming book (Duke University Press 2018), Cooking Data: Culture and Politics in an African Research World, draws on ethnographic fieldwork in Malawi with demographic projects in sites ranging from questionnaire design meetings, training for data collectors, fieldworker-led data collection in the field, and policy venues to critically examine the criteria and metrics that give numbers legitimacy in the era of global health.