Involving stakeholders at an early stage of learning environment design enables researchers to base a system around the needs of learners. By working directly with learners, researchers gain insight into learners' everyday problems when mastering difficult material, which complements their knowledge of educational theory. This approach is particularly fruitful when designing innovative systems which require new representations of complex concepts. This paper describes the development process of Adventure Author, an interactive story making environment for children. It focuses on the learner centred design methods used to develop a representation of interactive story structure for the user interface. Early consultation with our users around low and high-tech prototypes ensured that the representations we proposed could be comprehended and subsequently generated by children in the target age group. Keywords. Learner centred design, children, interactive storytelling