Accommodation is a mental process where an individual adjusts their cognitive schemas to fit in new and relevant aspects of their environment.
Accommodation in Piaget's Theory of Cognitive Development
According to child psychologist Jean Piaget, accommodation occurs when a child needs to take in new information that does not currently fit in with their existing schemas.
For example, a child with a pet dog, who has an existing mental schema of four-legged, furry creatures being dogs, may visit a zoo and encounter other, different types of four-legged furry creatures. His existing knowledge will cause him to think, at first, that they are all dogs, but when he learns that they are not dogs but other creatures (bears, tigers, etc.), he will need to modify his existing schema to have an overarching category of animals, of which a sub-category will be dogs.
Together with the process of assimilation, this mental adjustment would result in a more sophisticated level of thought, and a higher level of adaptability.
In Piaget's theory of cognitive development, accommodation and assimilation were the key equilibrative processes for all changes associated with development.