Over the last decades, the Organisation for Economic Co-operation and Development (OECD) has acquired an increasingly relevant and authoritative role in the global governance of education. The influence of the OECD in education owes much to the greater focus of this international organization on the production of new sources of quantitative data, and to the comparative perspective through which these data is approached (Grek, 2009; Martens & Jakobi, 2010). This shift has been driven by different data-gathering initiatives, among which the Programme for International Student Assessment (PISA) stands out. Since its first edition in the year 2000, PISA has been administered every three years in an increasing number of countries. Nearly 80 countries have participated in the 2018 edition. According to different observers, PISA has represented a turning point for the OECD and has consolidated its leading role within the global education field (Niemann & Martens, 2018). The success of PISA relies, on the one hand, on its capacity to commensurate complex educational processes, such as teaching and learning, in concrete numerical indicators and, on the other, on the country comparisons that result from this quantification exercise (Martens, 2007; Grek, 2009).