Primary Sources

Primary sources are those where most of the information being reported is presented for the first time. The writers will have been participants in or direct observers of the events or phenomena they describe. Look for a description in the article (or book, etc.) on the methods the author used in his or her research. It should include direct observation and/or original data gathering.

The 'original' primary literature - particularly in the sciences - includes:.

Secondary Sources

"Pointer" bibliographic literature and data collections, including:

NOTE:An information source (article, book, etc.) may contain a mixture of both primary and secondary information. For example, most scholarly articles begin with an introduction and/or review of the literature. This would be the "secondary" information. Then the author goes on to describe their methods and finally the results, with discussion and/or conclusions. This would be the "primary" information. For example, see the article Spread of introduced Lehmann lovegrass Eragrostis lehmanniana Nees. in Southern Arizona, USA" by Anable, McClaran, and Ruyle, in Biological Conservation, Volume 61, Issue 3, 1992, Pages 181-188.

Peer-Reviewed Literature

 Peer-reviewed journals (also called refereed or juried journals) send submitted articles to one or more experts for review before deciding to publish them. This review process helps ensure that published articles reflect solid scholarship in a field. Most often, the experts reviewing the article make critical comments on the text, comments that the author must incorporate into the article before its publication.

While not all scholarly journals are peer-reviewed, it is usually safe to assume that a peer-reviewed journal is also scholarly.

By looking at a journal issue, you can find indicators of peer-review. Many times in the "Information about the Journal" section, it will state that the articles are peer-reviewed. Also, if you see a list of Editorial Board members, that typically indicates peer-review. [For an example, see the "Publisher website" for Advances in Environmental Research.]