Adaptive learning systems attempt to provide personalised learning content and activities to meet the individual needs of learners as they progress through their studies. The promise is that they can move education onwards from the ‘one-size-fits-all’ approach, which attempts to teach students with widely differing levels of skills and abilities the same things at the same time during a course of fixed duration. 1 Traditional learning methods often provide an experience that is either too easy or too hard and can therefore demotivate learners who become bored or frustrated. Online systems can potentially customise aspects of the learning such as its pace and preferred type of media. The content can be targeted at the most appropriate level for the learner, so that it is ‘doable but challenging’ 2 in a way that human teachers, even with small groups, may not have the capacity to provide for each of their students. 3 Meanwhile, the models can be continuously refined by harvesting the data of the thousands of students who use them. 4