According to Jeremy Harmer (1998), students, like the rest of us, need to be able to do a number of things with a reading text. They need to be able to scan the text for particular bits of information they are searching for. This skills means that they do not have to read every word and line, on the contrary, such an approach would stop them scanning successfully.
Students need to be able to skim a text – as if they were casting their eyes over its surface – to get a general idea of what it is about. Just as with scanning, if they try to gather all the details at this stage, they will get bogged down ad may not be able to get the general idea because they are concentrating too hard on specifics.
Whether reader scan or skim depends on what kind of text they are reading and what they want to get out of it. They may scan a computer manual to find the one piece of information they need to use their machine, and they may skim a newspaper article to get a general idea of what’s been happening. But we would expect them to be less utilitarian with a literary work where reading for pleasure will be a slower, closer kind of activity.
Reading for detailed comprehension, whether looking for detailed information or language, must be seen by students as something very different from the reading skills mentioned above. When looking for details, we expect students to concentrate on the minutiae of what they are reading. One of the teacher’s main functions when training students to read is not only to persuade them of the advantages of skimming and scanning, but also to make them see that the way they read is vitally important.