Some thoughts on school size and its effects on adolescent development.

What do we know about the effects of school size on adolescent development? This article addresses this issue, based on a review of the available evidence. While this evidence is sketchy, it does offer three important hypotheses to guide our efforts to understand the human ecology of adolescence. First, school size matters, particularly to academically marginal students. Second, school size is not a simple linear effect. Rather, it involves a "threshold effect," so that increases in size above roughly 500 (in a secondary school) do not have an appreciable effect. Third, recent trends have "conspired" against youth by simultaneously producing larger schools - so that most schools are above the size threshold - and "forcing" ever larger numbers of academically marginal students into these secondary schools. This article explores these hypotheses and their significance for youth development.