Public/Private Ventures' (P/PV's) "GroundWork" series summarizes available evidence on a variety of social policy topics, providing a firm foundation for future work. This second brief in the series presents an overview of issues surrounding the ninth grade transition: why it is so important; why many middle school students find it so difficult; traits related to a successful transition; and what schools can do to ease difficulties in the transition. Research indicates that students unprepared to handle the transition are more likely to disengage from school, which in turn may lead to dropping out--and a host of related problems, thus perpetuating a cycle of poverty for disadvantaged, low-income youth. (Contains 2 endnotes.)