Primary sources in the social sciences differ from those used in the humanities. This page from Drew University points out what primary research articles in the sciences look like.
Characteristics of peer reviewed primary sources include the following:
1. Report original research, ideas, or scientific discoveries for the first time 2. Report results/findings/data from experiments or research studies 3. May also be referred to as primary research, primary articles, or research studies 4. DO NOT include meta-analyses, systematic reviews, or literature reviews. These are secondary sources 5. Should explain the research methodology used (randomized controlled trial, etc) 6. Frequently include methods, results, and discussion sections 7. Are factual, not interpretive
Adapted from http://libguides.lib.msu.edu/scienceprimarysources