Struck by his GCSE students' bewildered expressions when studying source extracts, Liam McDonnell decided to adopt a new approach to source analysis. Inspired by the work of other history teachers, McDonnell decided to use an anthology of substantial sources when studying nineteenth-century Whitechapel in London. By revisiting the sources at several points across the enquiry, McDonnell found his students revising and improving their original judgements as their knowledge of the sources and of the historical context grew.