Jacob Olivey wanted Year 8 to know that ordinary people in the nineteenth century constructed their own identities. In this reflection on how his practice developed in his training year, Olivey illustrates the importance of using historical scholarship in choosing foundational knowledge to teach. He shows how he used that scholarship to shape and re-shape the flow of a lesson sequence and to discern what pupils had and had not understood. Interpreting pupils' written and oral responses in the light of historians' work on working-class identity construction, Olivey advances history teachers' debate on teaching 'similarity and difference' enquiries. First, he suggests that if we ask pupils to judge the analytic value of a substantive concept to an historian "simultaneously" with exploring why past actors used that concept themselves, it may confuse the direction of the enquiry; second, following Hammond in TH157, he suggests that enabling pupils to understand and deploy a substantive concept such as 'class' requires familiarity with more concrete detail than we might think.