A primary source in the sciences is a document that describes original research. It is not an interpretation or analysis or someone else's research. It is written by the scientist who conducted the research. Key terms to look for are: methodology, results, conclusions, and references.
Primary sources are often peer-reviewed journal articles. Click on the 'Find Articles' tab for a list of useful databases.
The following terms are common indicators that a journal article is a primary source:
Avoid summaries or interpretations of research, also known as literature reviews. These are considered secondary sources because they do not present original information.