An overview of the History Learning Project, showing what the University of Indiana has been doing to reconstruct what students need to be able to do in history courses in the U.S - to deal with primary sources and to present historical arguments. The presenters showed clips from their “bottleneck” interviews and then followed their process of breaking down the operations that are required to get past these bottlenecks, developing ways to model these operations, and measuring the learning, with a focus on how this actually plays out in the classroom.