Journal articles are either primary or secondary research. Primary research refers to original research.
Primary research, or Empirical research, records direct observations or experiences. Empirical research can be analyzed quantitatively or qualitatively. Empirical research is published in books and in scholarly, peer-reviewed journals.
Most library databases do not offer straightforward ways to locate empirical research. Using "empirical" as a keyword will find some studies, but miss others. Some useful keywords are:
In any database always choose “Advanced Search.” Most databases allow you to limit your results to Document Type and/or Publication Type. You will find these categories if you scroll down on the advanced search page.