In 2006 the Danish government launched a programme “Equal opportunities for all children”, a programme aiming at bridging a widening national educational gap, a gap also identified and highlighted by PISA. One government target is to ensure that in 2015, 95% Danish pupils will pursue further education. The target is a highly ambitious one, and, according to several Danish researchers, a difficult one to reach. For while we are becoming increasingly good at identifying and explaining factors leading to social and educational inequity, we still know very little about successful intervention. What works for whom? In which contexts does it work? How does it work? Why does it work? And how can we benefit nationally and internationally from a local study of what causes one specific mechanism to work for one particular group of children? Taking its point of departure in a project carried out in collaboration with a suburban Copenhagen school district, our paper addresses some of these questions. Our argument is that we need to focus systematically and carefully on interrelated concepts of context, mechanism and outcome. As our project is in its first of three years, the paper will mainly address central issues of design and methods.