Formative assessment has gained substantial ground in the last ten years, together with a number of considerable promises that have been made about its potential to promote student learning. The recent drive towards Assessment for Learning and assessment for 21st Century skills raises a set of new challenges for both teachers and students alike. These challenges are related, on the one hand, to progress monitoring that results in responsive teaching or support activities, and on the other hand to the development and implementation of technologies that will allow (semi-) automated and personalised assessment systems. New data sources collected from such software will open new doors for formative assessment practices and related feedback types.