Very often the reader is involved in the use of reading for the sole purpose of extracting specific information. In other words, the reader, for example, may look at a piece of written language not in order to understand it all, but for the purpose of finding out only one or two facts. He may quickly read a film review only to find out the name of the star. The listener may turn on the radio and listen only for a particular item of news that he wants to hear. In both cases the reader/listener will disregard everything except the information he is interested in. This skill when applied to reading is often called scanning.
We may want to see what’s on television this evening at 8 o’clock. We are unlikely to start reading from the beginning of the list of programmes - starting with what’s on at 6 o’clock in the morning! Instead our eyes move quickly over the page until we find 8.00 p.m. and start reading the details of the programmes. In other words, we scan the page until we find what we ´re looking for.
How do you read certain types of material in your native language (directories, menus, timetables, small advertisements, etc).
When reading such texts you would normally expect to know what you are looking for beforehand. Most of the text does not need to be read.
Scanning exercises might ask students to look for names or dates, to find a definition of a key concept, or to list a certain number of supporting details. The purpose of scanning is to extract certain specific information without reading through the whole text.