Tangible User Interfaces (TUIs) offer the potential to facilitate collaborative learning in new ways. This paper presents an empirical study that investigated the effects of a TUE in a classroom setting on task performance and learning outcomes. In the tangible condition, apprentices worked together around an interactive tabletop warehouse simulation using tangible inputs. In the paper condition, they performed the same activity with only paper and pens. Results showed that the tangible condition resulted in better task performance (more alternative solutions explored and better final solution) but did not affect learning outcomes, i.e. understanding of important concepts and applying them to a problem-solving question. We discuss reasons for this in terms of task structure and type, nature of tangible user interfaces and effective interaction requirements.