In the sciences, primary research articles:
To identify whether an article in a peer-reviewed journal is a primary research article, look for some internal clues:
These are all indications that an article is a primary research article ("primary" because the experiments were carried out by the researchers who wrote the article).
Literature reviews (also called review articles) are articles that summarize and synthesize primary research articles on a topic.
Literature reviews are a good starting point when researching a topic because they provide:
There are several criteria that can help you to identify literature reviews:
Note: Many primary research articles include a short section that summarizes pertinent scientific literature as background for the paper. This isn't the same thing as a literature review article or review article, which is entirely devoted to a summary of primary articles.