Scholarly sources (whether books or articles) are written by and for experts in a field of study, frequently professors or academic researchers. They can be challenging to read and understand because they use the language of the field and terminology that may be unfamiliar to those outside the discipline, but they are considered reliable because the contents are written by specialists and peer-reviewed (reviewed by specialists) before publication. Scholarly sources also tend to delve deeply into a subject, often a narrowly defined subject. Scholarly sources may be published by a university press, a scholarly organization, or a commercial publisher (such as Kluwer Academic or Blackwell). Though scholarly sources may provide an overview of the subject, they generally focus on a specific issue or argument and generally contain a great deal of original research.

In contrast, popular sources are written to entertain and educate the general public. For the most part, they are written by journalists who have conducted research and interviewed experts. They may include original research, especially on current events or emerging trends. Mainly, though, they report on and summarize original research and are written for interested, nonspecialist readers.

Of course, popular sources range widely along the reliability spectrum. Highly respected newspapers and magazines, such as the New York Times, the Guardian, the Economist, and Harper’s Magazine, publish original research on news and culture. These newspapers and magazines check facts carefully and are often considered appropriate sources for research projects in entry-level courses (although you should check with your instructor to find out her or his expectations). Magazines that focus on celebrity gossip, such as People and Us Weekly, are unlikely to be considered appropriate sources for a college-level research project.

Trade publications—periodicals that report on news and technical advances in a specific industry—are written for those employed in the industry and include such titles as Advertising Age, World Cement, and American Machinist. Some trade publications may be appropriate for college research projects, especially in the sciences, but keep in mind that these publications are intended for a specialist audience and may focus on marketing products to professionals in the field. Table 25.1 summarizes some of the important differences between scholarly journals, popular magazines, and trade publications.