A primary research source is a paper in which authors give the first thorough description of their study and results.
Typically, in the field of psychology, a primary source that reports research is a type of journal article.
Journals publish compilations of articles that are reviewed by experts in the field before being accepted for publication.
If you look through a psychology journal, you may see some articles that are primary reports of research results.
The article will have an introduction, where the authors provide a context for their experiment by describing previous theory and research.
It will include a methods section with descriptions of the participants and procedures of the study, and a results section where the findings are described and analyzed statistically. Often the results section includes tables or figures.
The discussion reviews the findings, connects them with prior work, and raises further questions.
Not all journal articles report primary research.
Text copied from http://libguides.iusb.edu/content.php?pid=178323&sid=2575804
About psychology secondary sources
Textbooks, encyclopedias, most other books, and magazines are not primary research sources.
The magazine Scientific American is not a primary research source.
Journals such as Science or Nature include primary research articles (often you have to read the notes at the end to get information on methods); they also include other articles and letters that are not primary research sources.
Books that are edited and have chapters that describe research are usually not primary research sources.
Web sources may describe research but unless the source is a web-based publication, it is not a peer-reviewed description with the legitimacy of a journal article.