What makes middle school and middle schooling distinctive, if anything?

One type of criticism confronting the growth of middle schooling in Australia is that it lacks clear definition, offers nothing new, and is indistinguishable from what many primary and secondary schools already do. Against the background of that criticism, this paper examines whether or not middle schools and middle schooling do have a distinctive clientele, organisational position and philosophy that give them a unique rationale and imperative. It does so with reference to the international literature and what happens on the ground in this country. The paper begins by arguing that many recommended arrangements, principles and practices for middle schools apply equally to students of all ages and developmental stages. It then outlines seven possible sources and areas of distinctiveness that, could they be shown to be valid, would help make middle schools and middle schooling adolescent-specific rather than generic