Primary source research articles are also known as empirical studies. According to thePublication Manual of the American Psychological Association, Sixth Edition (p. 10):
Empirical studies are reports of original research. These include secondary analyses that test hypotheses by presenting novel analyses of data not considered or addressed in previous reports. They typically consist of distinct sections that reflect the stages in the research process and that appear in the following sequence:
- introduction: development of the problem under investigation, including its historical antecedents, and statement of the purpose of the investigation;
- method: description of the procedures used to conduct the investigation;
- results: report of the findings and analyses; and
- discussion: summary, interpretation, and implications of the results.
To search PsycINFO for empirical studies, there is a limit on the Advanced Search screen, toward the bottom:
Note: selecting that option does not guarantee all your results will be exclusively empirical studies. You'll need to read the article very carefully to ensure you have found original research. Further, you may need to track the citation backward to find the citation for the original research (This is a research strategy called cycling.) See the video link on the right for a demonstration of how to search methodologies in PsycINFO.
Look at the following two examples of empirical studies.
According to the Publication Manual of the American Psychological Association, Sixth Edition (p. 10):
Literature reviews, including research syntheses and meta-analyses, are critical evaluations of material that has already been published. In meta-analyses, authors use quantitative procedures to statistically combine the results of of studies. By organizing, integrating, and evaluating previously published material, authors of literature reviews consider the progress of research toward clarifying a problem. In a sense, literature reviews are tutorials, in that authors
- define and clarify the problem;
- summarize previous investigations to inform the reader of the state of research;
- identify relations, contradictions, gaps, and inconsistencies in the literature; and
- suggest the next step or steps in solving the problem.
The components or literature reviews can be arranged in various ways (e.g., by grouping research based on similarity in the concepts or theories of interest, methodological similarities among studies reviewed, or the historical development of the field).
A video tutorial to searching PsycINFO by methodology - literature reviews, empirical research, etc.