More than half of Prince George’s County‘s most disadvantaged middle schools had two or more changes in leadership during the past five years and only a handful were led by principals with any managerial experience prior to assuming their posts, according to a study released this week.

The study, by the Baltimore-based Advocates for Children and Youth, looked at 14 of the county’s 32 middle schools. They were identified because of high poverty and low performance on state assessment exams used to determine Annual Yearly Progress under federal No Child Left Behind regulations.