This brief paper introduces a new approach to assessing the trustworthiness of research comparisons when expressed numerically. The 'number needed to disturb' a research finding would be the number of counterfactual values that can be added to the smallest arm of any comparison before the difference or 'effect' size disappears, minus the number of…

This article emerges from a recent review of evidence, conducted by the authors and others, on the lifelong barriers to widening participation in higher education in England. This has led us to a consideration of the quality and relevance of the research activity in this large field of endeavour, and to the creation of a typology of the kinds of…