The purpose of a site is the reason for the information being there - the aim of the site. One has to ask oneself, "Why did this person publish this information?". Not all web sites have a clear statement telling you about their aims. You may need to look for other clues, such as:

• Are they trying to convince us about something, for example, to buy something or to believe something?
• Is it a government information site or a university site (these are normally quite reliable sources of information and their purpose is to share the information)? However some government sites may present a particular political perspective.

Advertising on Web sites is a common phenomenon. Advertising is not necessarily a bad thing on a Web site. People managing Web sites that you can access free on the Internet, make use advertising to pay for the costs of running the site.

When you use the Internet, read the newspaper or watch television it is important to distinguish the advertising from the other content.

Whereas assessing the accuracy of the site, detecting bias and finding out who the authors are may sometimes be quite simple tasks, trying to find out the purpose of the site is often something you have to infer, deduce or even guess.