Illustrations are numerous and colorful. Authors cite their sources in endnotes, footnotes or bibliographies. Individual issues have little or no advertising. Articles must go through a peer-review process. Illustrations usually take the form of charts and graphs.
Articles use jargon of the discipline.
For some assignments you need to think about whether or not point of view is important. If you are debating an issue or writing an opinionated essay for example, you will want to consider a particular view, opposing viewpoints or a range of viewpoints. If you need to be objective however, be aware of bias when evaluating your sources. Different research assignments will require the use of different types of sources. Primary sources include original materials and firsthand accounts, which have not undergone interpretation or change.