Disparities in college access for underrepresented urban students are one of the most urgent educational problems of America's education system. In response to growing national concern, this longitudinal study investigated how school leaders worked collaboratively with key stakeholders to implement research-supported student services in order to…

This paper examines how controlling statistically for baseline covariates (especially pretests) improves the precision of studies that randomize schools to measure the impacts of educational interventions on student achievement. Part I of the paper introduces the concepts, issues, and options involved. Parts II and III present empirical findings…