Teachers have the ability to influence each of these layers, and so designing pedagogy becomes a more complex - but potentially more rewarding - task. This is vitally important so that we can evaluate and appraise pedagogies from an authentic position, rather than trying to pretend that all pedagogies aim at the same goals. The above account also established that both discipline-centric and student-centric pedagogies are fundamental to achieving the purposes of education: the study of how expertise develops and of ‘cognitive load’ highlights that explicit teaching of knowledge and skills is a vital part of education.