Children from low-income and ethnic minority backgrounds have demonstrated substantially lower levels of math achievement than their middle class majority peers for decades. The present study addressed two research questions: (1) when used as a supplement to typical classroom instruction and in isolation from the larger curriculum, does Building…

Recent research on the design of social experiments has highlighted the effects of different design choices on research findings. Since experiments rarely collect their samples using random selection, in order to address these external validity problems and design choices, recent research has focused on two areas. The first area is on methods for…