Models are central to the practice and teaching of science. Yet people often fail to grasp how scientific models explain their observations of the world. Realizing the explanatory power of a model may require aligning its relational structure to that of the observable phenomena. The present research tested whether "relational…

Head Start is the largest publicly funded preschool program in the U.S., and one of its primary goals is to improve the school readiness of low-income children. As has been widely reported, the first randomized trial of Head Start in the program's history found some evidence that it is achieving this goal. Receiving one year of Head Start had…