Final answer:
Children interpret the external world through a process called assimilation, where they integrate new information into their existing mental models. When new information does not fit, they accommodate by adjusting their schemata. Assimilation and accommodation are different from object permanence, which is a separate developmental milestone.
Step-by-step explanation:
Children use their current schemes to interpret the external world using a process known as assimilation. When children encouter new information or experiences, they try to fit this new data into their existing mental models or schemata. If the new information fits well with what they already know, they simply assimilate it, thus using their current understanding of the world. On the other hand, when the new information or experiences do not fit into their existing schemata, they need to adjust their mental models through a process called accommodation.
For instance, if a child knows the schema for dogs and sees a new type of dog, they will assimilate this information into their existing dog schema. In contrast, if they see an animal that doesn't fit into any existing schema, like a platypus, they might have to accommodate by modifying their schema or creating a new one for this unique animal.
It is important to note that object permanence is a different concept that refers to a child's understanding that objects continue to exist even when they are not visible. This is something that develops in children generally around the age of 8 months during the sensorimotor stage in Piaget's theory of cognitive development.