Expansion and extension are two of the main types of conversational recasting. Recasting, which is sometimes called, “responsive modeling,” is used to describe a larger category of techniques used to add or correct a child’s utterance without interrupting the flow of conversation. Imitation and targeted questions are other types of recasting.
Expansion – Expansion takes what the child says, and adds grammar and semantics to turn into a comparable adult utterance. The point is to keep the communication flow going smoothly, while not making the child realize that he is being corrected.
example: The child’s “doggy house” may be repeated as,”That is the dog’s house.”
Extension – Extension takes what the child says and adds information. Extension is typically used in conjunction with expansions.
example: The child’s “doggy house,” may be repeated by caregiver as, “That is the dog’s house. He is a large dog.”
Expansion and extension are extensively confused. It helps for me to think of when a balloon expands, it stays the same. It does not add information or substance as would, say, an extension on a deadline.