Organization of Primary Research Articles and Review Articles

Scientific primary research articles are commonly organized as follows:

  • Abstract - brief description of the why and how of the research, as well as the results and main conclusions
  • Introduction - reviews the pertinent literature as background for the research subsequently described
  • Materials and Methods - how the research was done with enough specifics so it can be reproduced
  • Results - what was found, often supported with figures and tables
  • Discussion - what the results suggest or establish, how this research fits in with previous research, potential usefulness of this research, etc.
  • References - sources used

Author names and affiliations should also be included. 

Please note that these sections are based on tradition, not absolute rules.  The only absolute rules are those given by the journal publishing the article.  Section titles may vary or even not be shown, or sections may appear in a different order.  But this is the basic structure you should expect to see.

Review articles often contain some of the same sections as primary research articles, such as an abstract, introduction, and of course references. The most important difference you'll see when you read a review article is that it is about research previously done, and therefore is a secondary source.


The information on original research in this section is based on the article "How do I write a scientific paper?" from SciDevNet; check it out to get more details.

Identifying Primary Research Articles

Following are excerpts from a primary research paper published by PLOS One. Notice the types of information highlighted, which provide important clues for determining whether you're reading about a newly done experiment.

Take a look at the complete article "Digging the New York City Skyline: Soil Fungal Communities in Green Roofs and City Parks" to get a better feel for primary research articles.

Identifying Review Articles

Following are excerpts from a review article published in PLOS Genetics. Notice the types of information highlighted, which provides important clues for determining if you are reading a review.

Take a look at the complete article "Bacterial Toxin–Antitoxin Systems: More Than Selfish Entities?" to get a better feel for literature reviews.