This chapter focuses on the logics of data in the current neoliberal educational context and explains why reducing education to numbers is attractive, useful and ever more possible. The phenomenon of disciplinary power through calculation, numbers and statistics in the governance of education has been present since the advent of primary education. The chapter argues that concepts both of discipline and of control continue to have relevance in the study of data and education. Educational data science is a 'significant, albeit emerging and disparate' field of biopolitical intervention. The concepts of performativity, visibility and 'data doubles' or dividuals help us to analyse the productive and reductive aspects of datafication, particularly the data-driven subjectivities. The economisation of early years and primary education fulfils neoliberalism's fantasy and desire to collapse the purposes of education into a market-based quantitative competition of winners and losers. The chapter concludes with a description of research strategies and sites and a reflection on researching data in education.