For more than three decades judgements of schools' quality have been dominated by the frameworks, developed by members of Her Majesty's Inspectorate (HMI). This article reviews the approaches employed in the national survey conducted for the Plowden Committee, subsequent surveys undertaken by HMI during the seventies and eighties and the changes brought about by the advent of the Office for Standards in Education (OFSTED) in the early nineties. The frameworks employed appear to have changed from one decade to the next, (...) sometimes subtly, at other times more radically. Overall, such changes have been sufficiently major for it to be difficult, if not impossible, to make anything other than the broadest statements about changes in the state and quality of the nation's schooling over time. (shrink)