There is an increasing interest in using digital technologies to create interactive learning environments (ILEs) that both teach and assess student skills that are hard or impossible to assess using ‘static’ items such as traditional, multiple-choice questions. These interactive learning environments try to do two things simultaneously: firstly, to monitor the learning of the student in real time, providing feedback to help the student progress through the learning task; and secondly, to use the information gathered during the learning to make judgements about where the student is in learning of the topic. Essentially, ILEs draw upon the same source of data — the interactions of the student with the learning materials and embedded assessment tasks — to perform these measurements. To make these kinds of decisions, ILEs collect and analyse many variables; the complexity of these data demands the use of sophisticated assessment methods that differ from those used in traditional paper-and-pencil tests. The complexity of the ILEs also introduces challenges such as students becoming confused or failing to comprehend the feedback from the system. Through reference to examples of ILEs, this session shows how assessment of learning takes place, how such assessment can provide valid and reliable measures, what we are learning about students’ use of the systems and how we are working to refine the systems of the future.