The overarching theme in his program of research is an examination of how people learn through activity. Learning through activity involves interacting with other people, physical objects, and ideas. Physical objects can range from actual flowers and drawings that label their parts to computer simulations. Similarly, ideas include individual beliefs and preferences, the rules that groups such as classrooms follow, and historically developed concepts that span generations. His research examines how individuals coordinate their actions and ideas within these complex settings, and how this can lead to learning. A major focus of Joshua's work has been examining how young students (5-7 years old) create representations while learning about complex science concepts.