What Is Skimming?

Skimming is one of the tools you can use to read more in less time. Skimming refers to looking only for the general or main ideas, and works best with non-fiction (or factual) material. With skimming, your overall understanding is reduced because you don’t read everything. You read only what is important to your purpose. Skimming takes place while reading and allows you to look for details in addition to the main ideas.
How to skim. Many people think that skimming is a haphazard process placing the eyes where ever they fall. However, to skim effectively, there has to be a structure but you don’t read everything. What you read is more important than what you leave out. So what material do you read and what material do you leave out?
Let’s say you are doing research on a long chapter or a web site. By reading the first few paragraphs in detail, you will get a good idea of what information will be discussed. Once you know where the reading is headed, you can begin to read only the first sentence of each paragraph. Also called topic sentences, they give you the main idea of the paragraph. If you do not get the main idea in the topic sentence or if the paragraph greatly interests you, then you may want to skim more.
At the end of each topic sentence, your eyes should drop down through the rest of the paragraph, looking for important pieces of information, such as names, dates, or events. Continue to read only topic sentences, dropping down through the rest of the paragraphs, until you are near the end. Since the last few paragraphs may contain a conclusion or summary, you should stop skimming there and read in detail. Remember that your overall comprehension will be lower than if you read in detail. If while skimming, you feel you are grasping the main ideas, then you are skimming correctly.
When to skim.Because skimming is done at a fast speed with less-than-normal comprehension, you shouldn’t skim all the time. There are many times, however, when skimming is very useful.
Suppose you are taking a presentation skills class and have to deliver an oral report in a few days about the first computers ever made. You locate six books and four newspaper articles about this topic. Because you must be ready soon, you do not have time to read each word, but you need a large quantity of solid information.
Skimming will help you locate the information quickly while making sure you use your time wisely. It will also increase the amount of usable material you obtain for your research.
Suppose you have an exam in a few days. You need to review the material you learned, but you don’t want to reread everything. By skimming, you can quickly locate the information you haven’t mastered yet and study only that material.
While reading, ask yourself the following questions to help you decide whether or not to skim. If you answer yes to any of these, then skimming is a useful tool.
■    Is this material non-fiction?
■    Do I have a lot to read and only a small amount of time?
■    Do I already know something about this?
■    Can any of the material be skipped?
If you have sufficient background knowledge or believe you don’t need the information, then skip it! That’s right—don’t read it at all! Believe it or not, skipping material may sometimes be the best use of your time. Just because someone wrote something doesn’t mean you have to read it.  If you pick and choose carefully what you skim and skip, you will be pleasantly surprised at the large amount of information you can get through in a short period of time.

Source : http://www.howtolearn.com/2013/02/skimming-and-scanning-two-important-strategies-for-speeding-up-your-reading/