What’s the secret of deeper learning? Over a century ago, John Dewey gave it away: we have to do something with what we want to learn about. In a new book called Changing the Subject, the High Tech High network of K–12 schools shares 50 inspiring hands-on projects that cross grade levels as well as subject areas. In this episode, Rob Riordan (known as the “Emperor of Rigor” at HTH) explores the transformative power of such work.