A crucial human cognitive goal is to understand and to be understood. Five studies are proposed to investigate several basic processes of understanding that emerge in early development. The studies encompass three foci. (1) Explanatory understanding: When and how do children genuinely seek and learn from causal explanations (beyond using why- and how-questions to merely seek attention and social engagement)? (2) Monitoring one’s understanding: When and how do young children actively monitor their understanding of social-communicative interchanges and seek to clarify and correct potential misunderstandings (as opposed to merely attend, act, and comply or resist)? (3) Understanding information from "smart" technology: Even young children increasingly live and interact with smart technology—cell phones, computer tablets, robotic devices. When and how do they accept and understand such information? This will be studied by examining children’s acceptance and understanding of information provided by social robots, robots with quasi-human-like features and interactive capacities.