The only valid reason for teaching is to bring about learning. Thus, in considering the challenges to be faced in teaching the model-based curriculum, it is necessary to consider what successful learning in the field might entail. This may be divided, if only for convenience, into ‘having an acceptable understanding of what a model is,’ ‘having a developed capacity to mentally visualise models’ and ‘having an acceptable understanding of the natures of metaphor and analogy.’ Taking each of these in turn: