In order to explain how we draw on our existing knowledge in comprehension, cognitive psychologists such as Bartlett (1932) have come up with the term schema. Schemas (or schemata) are simply frameworks of concepts stored in long-term memory which represent our current understanding of the world. They are constantly being updated as our knowledge and experience changes.

For example, relating back to our earlier example, your schema for the word 'hospital' probably associates it with a place where you go with serious injury or disease. However, after a conversation with hospital staff, or after hearing repeated reports of violence in hospitals in the news media, you may add to your hospital schema the idea that they are places where staff get attacked!

The process of comprehension, then, relies on our matching the input we hear to existing schemas. Schemas determine our expectations and provide the context for interpreting linguistic information quickly and efficiently. They obviate the need for listeners to process every word spoken before getting the essential meaning. They relieve speakers of the need to state details which may plausibly be assumed to be shared by the listener.

Of course, as we comprehend, we may notice new information in written or spoken input, and modify our schema as a result. However, comprehension simply breaks down when we cannot link incoming linguistic information to an existing schema, or if we have selected the wrong schema for its interpretation.