Designing technologies for learning is a complex task. Learning is sensitive even to the smallest changes in the design and, reciprocally, what individuals bring to the artefacts we design is hugely varied, making it difficult if not impossible to predict how learners will use them. A further challenge is that a piece of information or a concept instantiated within a dynamic interactive system is only superficially the same as one presented using static technologies such as pencil and paper. Researching, developing and evaluating the appropriate technologies for a given learning setting is therefore a complex, multidisciplinary and iterative process. We study the interaction between the technologies that we design and learners' evolving understandings.