Now you see it, now you don't : school effectiveness as conjuring?

Abstract

This paper considers the contextualised value-added scores of all secondary schools in one LEA in England over five years. It shows that only 2 out of 30 schools had a consistent run of either positive or negative value-added scores, and that this number is no more than would be expected by chance even if the scores were meaningless. Value-added results may seem more impressive and more consistent than this to some observers because they are, probably inadvertently, presented after the event as a kind of conjuring trick. But if this kind of ‘school effect’ is as transitory as this case study of one authority suggests, then it is not something that can form an ethical basis for policy or practice decisions. Until the situation is much clearer, parents should not be encouraged to choose, nor inspectors to judge, schools on this basis.