Image created by Laura Cameron

Peer review is the process by which articles or other works are critiqued before they are published. Authors send articles to an editor, who decides whether the work should be forwarded to reviewers for the journal. The most stringent form is anonymous or blind review, where neither the author nor the reviewers know whose work is being examined by whom. This helps reduce bias.

Reviewers are usually well-published researchers and experts themselves. The articles are sent back to the editor with remarks and recommendations, usually 1) publish as is (rare), 2) publish if edited or changed in specific ways, or 3) don't publish. Editors will usually go with the recommendation of the majority of the reviewers. If revision is recommended, the reviewers' comments may be returned with the draft. Authors who have been asked for revisions normally make the recommended changes and resubmit the article to the editor.

The process is intended to improve the content of studies published-- more eyes on a project, and one's reputation on the line with peers, tends to improve the quality of what's published.  There are cases where it hasn't worked, and critics of the cycle, but it is the best system that has been developed to this point.

Image created by Laura Cameron, Education Librarian

What is considered a primary source varies somewhat by discipline. In any case, think of a primary source as first-hand knowledge, eyewitness accounts,or reports about a specific topic.

• In the arts - a piece of art, such as a painting or sculpture, a musical score, a poem, a book or chapter, or an essay--whatever is created by the artist, writer, photographer, etc.
• In the sciences - the first report of research; it may be published as a journal article, or sometimes as a research report or conference presentation
• In some of the social sciences - a primary source may be the first report of a piece of research, especially of empirical studies, or it may be something closer to primary sources in history, since some areas of these fields depend on direct observation, data, personal narratives or commentary, as from interviews or case studies.
• For history - a primary source is a letter, a diary, speech, lecture, piece of legislation, document or manuscript-- an original source which forms the basis, with other sources, of secondary work, such as a study of life in eighteenth century Ireland

A secondary source is based on a primary source or other sources. It includes analysis, criticism, or other intellectual input. Secondary sources can include books, book chapters, articles, especially literature reviews, and some book reviews.

A tertiary source is commonly a resource or tool that helps people find primary or secondary sources. Tertiary sources include most bibliographies, databases and indexes, and library catalogs.