Aurelia was explaining problem sets to three undergraduates who sat in the Teaching Assistants’ office. It was the same three who’d come before the last quiz. Their scores had improved by an average of five points each, and they had returned, hoping to continue the trend.  “So in a Boolean model, this would be ...” Aurelia began. “True!” they cried. “Yes!” Aurelia was energized by their responsiveness. Not only were they listening to her, but they were processing what she