At the start of preschool, four-year-old pupils differ in their development, including in their capacity to self-regulate their playing and learning. In preschool and primary school, educational processes are generally adapted to the mean age of the pupils in the class. The same may apply to pupil-monitoring systems based on information and communication technology (ICT). This normbased factor undermines the potential of ICT to support the educational differentiation needed for pupils and increases the amount of daily work for teachers. A theoretical framework is sketched in which pedagogical-didactical, organisational and ICT guidelines enhance differentiated, self-regulated playing and learning for each pupil within preschool and primary school. To develop and check such optimal education and ICT conditions in practice, a pilot and a randomised intervention study are carried out in integrated Dutch preschools/primary schools for pupils aged 4-12. Pilot results support the use of a procedure to screen each child's characteristics at the start of preschool by parents and preschool teachers, and also the immediate relevance of criterion-based and norm-based ordering ('double diagnostics') of playing and learning materials. Final attention is given to the intervention study and further development of optimal education in a European research context.