The Center, as one of a handful of institutions conducting research on education in sub-Saharan Africa, has made substantive contributions to the understanding barriers to schooling, quality in teaching, and measurement of learning outcomes – especially among poor and marginalized populations in both urban and rural East Africa. Intervention models piloted during the last strategic period looked to improve retention of adolescent girls and boys in school and to encourage transition to secondary school among some of the populations most vulnerable to discontinued schooling: