Using various official sources (such as Ofsted reports), the article explores competing conceptions of the under-achieving school which have been operationalised in recent years. It suggests that there have been multiple, potentially conflicting definitions in policy discourse to which recent innovations have merely added a further layer of complexity. Using a simple conceptual framework comparing judgements made within standards and progress frameworks for evaluating schools performance, it highlights the very limited range of conditions where judgements made within one tradition would complement those made within the other. As the educational system begins to turn increasingly to use of so-called value-added approaches as a way forward, the implications of these analyses for policy development, particularly in relation to the alleviation of social and educational disadvantage, are considered.