"Violation-of-expectation" is a research method used to study infant cognition. In this method, if an infant shows renewed interest or attention (dishabituation) to a stimulus that contradicts their previous experience or expectations, it suggests that the infant recognizes the new stimulus as surprising. It's like when a baby sees an unexpected event, like a ball passing through a solid wall in a puppet show, and shows heightened interest or surprise, indicating that they have some understanding of the unexpectedness of the event.