An ELT Glossary : Top-down processing

Using pre-existing "knowledge of the world" - eg knowledge of  discourse conventions, topic, cultural or social norms - in order to interpret meaning while reading or listening.
Eg :  If I hear "John is 18 and lives with his family in Leeds" - my interpretation of the make-up of John's family (mother, father, siblings) differs from the interpretation that I make if I hear "John is 48 and lives with his family in Leeds" (wife and children). The interpretation is, however, based on my knowledge of the world, not on the text itself, where the information is not explicitly stated..

For other examples of how this might happen see the related terms Schema and Inference, and for its application to the classroom see  the article Teaching Listening : Top Down or Bottom Up?   

Further reading

Lynch, T. Teaching Listening Comprehension, Oxford

(Don't forget that you can often find used copies of the books you want on Amazon at prices much lower than the advertised price).