I found this while building a human-centered dialogue system, adapting a colleague's research. The idea is simple: people don't know what they don't know. Sitting in front of a chat window, they don't know what to ask. They can't type the question. So the dialogue goes dark and they abandon it.
The usual failure looks like this — a person types something small, gets a generic answer back, doesn't feel understood, and walks away. No amount of model quality fixes a badly formed question. The fix is in the writing: the system has to draw them back in with curiosity, with a question that intrigues, with the conversational equivalent of a raised hand.
"Any teacher knows that silence means you've lost the class. You want those hands to go up. Interaction equals learning — and a chatbot is no different."