In many of your classes, especially in the sciences, your professor may specify that you should use primary sources or empirical articles. It is important to understand what that means before you begin your search.
Sources come in three types: Primary, secondary, and tertiary.
Peer-reviewed journals publish many things that are not primary sources, including:
Identifying a primary or empirical article takes practice. You have to carefully review each of the parts of the article.
Abstract: The abstract of an article is a short summary of the research. A primary source will have an abstract that includes a hypothesis and an active statement of research that the author(s) performed. Pay special attention to the way the abstract describes the type of research that was conducted.
Here is an abstract of a primary source. One of the big clues is the inclusion of participants in the study and the description of how the experiment was carried out.
Here is an abstract of a secondary source. The authors include an active statement of research, but the process they describe includes searching other people’s research and comparing multiple studies.
Methods: A Primary source should have a methods section. Secondary sources occasionally have a methods section, so be sure to read carefully to understand whether they did original research (lab work, clinical trial, interviews, surveys, analyzing historical records) or if they found and analyzed the research of others (the authors might discuss conducting a literature review or searching different databases).
Here is the methods section of a primary source, with excerpts from “participants” and “measures” sections. (Other primary articles might look different, but will include similar information)
Here is the methods section of a secondary article. Not all secondary articles will have a methods section, but if they do, it should outline the search process and qualities of studies that would indicate their inclusion in the research.
Results: A primary source should also have a results section, where the authors present the raw data that they collected. Some secondary sources will have a section labeled results that summarize their analysis of the primary sources they reviewed. Remember, if it is a primary source, there should be data collected from the study.
Here is an excerpt from the results section of a primary source. It reports data and trends in data that were gathered by the author(s).
Here is an excerpt from the results section of a secondary source. It reports the summary of data and data trends found in other studies, not directly conducted by the author(s).
The results section of a primary source will usually include tables, charts, and graphs that help to make the data more understandable. Some secondary sources also contain graphs or tables that explain the process they used to select which primary articles to review. Be sure that you understand what the table, chart, or graph is trying to show.
Here is a data table from a primary source. This table shows the data gathered from different treatment groups in the study.
Here is a data table from a secondary source. This table shows the details of the articles they included in their study.
Discussion: In the discussion section, a primary source will analyze and explain the results to draw preliminary conclusions and discuss how their findings compare to existing research.
Here is an excerpt from the discussion section of a primary source (case study). It discusses the evidence and outcome of a specific study conducted by the author(s).
Here is an excerpt from the discussion section of a secondary source. Some keywords include "exploratory examination" of other studies and "systemic review".
If you aren't sure if an article you've found is a primary source - ask a librarian!
Your professor is the final judge of whether an article is appropriate for a particular assignment, so be sure to discuss your source selection with them.