SummaryNeville Bennett's Teaching Styles and Pupil Progress has attracted widespread attention for its major conclusion that formal teaching styles foster greater pupil progress than more informal ones. The present paper examines the adequacy of the research on which this claim is based. It concludes that, at best, no valid conclusions can be reached on the basis of the published evidence. It questions the presentation and interpretation of the results and their ‘educational significance’, the manner in which the teaching styles were originally established and a sample selected for intensive study, as well as the statistical procedures by which the data were analysed. In addition the controls for external influences, such as the eleven‐plus, are shown to be inadequate by Bennett's own account. In this latter respect the effects of formal teaching and the eleven‐plus appear to be inextricably confounded. Given a research design that is so seriously flawed it is doubtful whether any meaningful conclusions can be drawn from the study.