ABSTRACT
Although the circumstances and contexts of schooling differ widely across the world, there is a fairly common view – held by governments at least – that schooling, in general, is increasing in cost and decreasing in quality. Although it is often difficult to investigate empirically the truth of these claims, they are constantly stressed by the popular media, with the result that reforms are introduced based more on ideological commitment than on research evidence. Findings from scientifically sound studies (especially where these are replicated, about the power of individual schools to promote or reduce their positive impacts are, therefore, of critical importance.
