Consider a Source's Purpose and Audience
Understanding the purpose and audience of a source will help determine its usefulness for your research project. A general reference source in a library serves a much different purpose than an editorial in a newspaper, an advertisement in a magazine, or a Web site providing information about a product or service.
Similarly, sources targeting an audience of experts in a particular field contain different kinds of information than those written for a general audience.
Those written for technical experts assume an audience with a great deal of background knowledge. Typically, these sources skip general treatments of a topic in favor of detailed discussions tailored to experts.
In contrast, sources written for general audiences provide background information for their readers.