A models and modelling approach was adopted to investigate the educational potential of a science museum exhibition. It focused on patterns of relationship between the teaching models proposed by designers and students models in regard to four exhibits concerning astronomical cycles. Student's models were elicited by interviewing 21 pupils selected from among those who showed a change of their models between pre-visit and post-visit questionnaires. Four patterns of relationship were identified, ranging from low to high degrees of convergence between designers and students. Exhibits designed by fragmenting the phenomena (analytical approach) tend to promote less convergent patterns than exhibits that maintain the complexity of the phenomena (synthetic approach). We argue that the two approaches are complementary: without synthetic models visitors find it difficult to identify the phenomenon addressed by analytical models, while the latter may bring to visitors' attention aspects that otherwise might be hidden by the complexity of synthetic models.