It is true that digitalisation has contributed to the rise in populism and the establishment of a post-factual world that can work against rational policy making. But the very same forces, whether in the form of more and better data or new statistical and analytical tools, have also massively expanded the scope and power of social research to create a more evidence-based environment for the development of effective policies. The first PISA assessment in 2000 was able to explain about a third of the performance variation among schools across the participating countries, but in 2015 that figure had risen to 85%. That means that most of the performance differences among schools can now be statistically associated and explained, with data from students, parents, teachers and school principals, even if the causal nature of many of those relationships remains still insufficiently understood. One reason for the difficulty in reforming education is simply the scale and reach of the sector. Schools are among the biggest areas of public spending.