The Fourth International Conference on Grey Literature (GL '99) in Washington, DC, in October 1999 defined grey literature as follows: "That which is produced on all levels of government, academics, business and industry in print and electronic formats, but which is not controlled by commercial publishers."
Types of grey literature may include:
Also known as scholarly, refereed, or peer-reviewed journals.
Appearance: Generally, the appearance is more sedate; the cover may even consist of the table of contents. The articles may contain graphs or charts, but likely few glossy photographs or other illustrations.
Language: Articles will be written using a more technical vocabulary, which may be specific to the subject matter.
Audience: These articles are written for scholars, researchers, or professionals in a particular field.
Author/Authority: The authors include researchers or scholars in a field who are generally reporting the results of their original research.
Citations: The articles include footnotes and a bibliography.
Content: Research based articles that usually contain an abstract, methodology, discussion, charts or tables, results, conclusions, and references.
Editing: Articles are reviewed by an editorial board or outside scholars before publications; often there are peer reviewers who referee the journal.
Frequency: Usually published monthly, bimonthly, or quarterly.
Also known as industry magazines.
Appearance: Generally, these magazines are appealing and include color illustrations, possibly photographs.
Language: Less formal than scholarly articles, the language will often include jargon particular to the industry.
Audience: These articles are written for professionals in a particular industry.
Author/Authority: Article authors are generally staff writers employed by the magazine, although industry professionals may submit articles.
Citations: Often footnotes and references are included in articles, but not always.
Content: News and special features of interest within a particular profession or industry.
Editing: Articles are generally reviewed by employees of the publication.
Frequency: Usually published biweekly or monthly.
Appearance: Appealing or eye-catching, these magazines include a number of advertisements and glossy photographs or illustrations.
Language: The language of these magazines will be more casual, often written at a high school level or lower.
Audience: Intended for the general public.
Author/Authority: Journalists or contributing authors, sometimes the author is not listed.
Citations: Citations are rarely included.
Content: General interest articles, news, or opinions.
Editing: Articles are reviewed by employees of the publication.
Frequency: Usually published weekly or monthly.
Primary sources are records of events or evidence as they are first described or actually happened without any interpretation or commentary. Information that is shown for the first time or original material on which other research is based is considered primary. These sources display original thought, report on new discoveries, or share fresh information.
Examples of primary sources:
Secondary sources offer an analysis or restatement of primary sources. They often try to describe or explain primary sources. They tend to be works which summarize, interpret, reorganize, or otherwise provide an added value to a primary source.
Examples of Secondary Sources:
Tertiary sources index, abstract, organize, compile, or digest other sources. Some reference materials and textbooks are considered tertiary sources when their chief purpose is to list, summarize, or simply repackage ideas or other information. Tertiary sources are usually not credited to a particular author.
Examples of Tertiary Sources:
When evaluating the quality of print or online information, consider the following:
Please give attribution to the University of Minnesota Crookston
