Human–Computer Interaction is often introduced as the study of how people use computers. That framing isn’t wrong, but it undersells the field. HCI studies what happens at the boundary between human intention and machine behavior: the moment a person forms a goal, expresses it through some interface, and waits to see whether the system understood.
For most of computing history, that boundary was a screen, a mouse, a keyboard: fairly legible surfaces where researchers could observe clicks, measure task time, and ask people to think aloud. Conversational AI changes the shape of that boundary. Instead of clicking a labeled button, people now type or speak an open-ended request and trust a model to infer what they meant.
That’s why CHAI Lab treats conversation itself as a design material. Tone, pacing, personality, and the phrasing of an explanation aren’t incidental details, they’re the interface. We think studying them with the same rigor HCI has always brought to buttons and menus is where the field goes next.