Tips for reading and interpreting primary literature!

This page will provide an overview and guide to the structure of (most) scientific papers, also called primary literature. CLICK on a topic below to read relevant information regarding each section.

What is "primary literature?"

You may not have had the opportunity to read a scientific paper yet, but you will begin to develop this skill in this course.

Scientific papers are important to become familiar with as you study science. Science is simply a way of knowing the about the physical and natural world that we live in. Specifically, science is a way of discovering new things about the physical and natural world by asking testable questions and addressing those questions with evidence (observations, measurements, models, etc.,).

You may have already learned that science is about the process of generating and testing hypotheses and that this process involves repeatability and experimentation. Often the scientific method is depicted as a straightforward process: pose a hypothesis, collect data to test the hypothesis, analyze data, draw a conclusion, communicate the results. It's actually much more of an iterative process of revising hypotheses and approaches and collecting data until enough evidence has been gathered to yield robust results that can be shared with the world.

This final step is the critical step of publishing original scientific results as a scientific paper which is published in a peer-reviewed journal. Original scientific results published in this way are also called the "primary literature." Peer-review is an important aspect of this process. Peer-review means that other scientists read, evaluate, and provide a review of the research to be published, including recommending it for publication or revision.

Scientific papers have a specific and predictable format. What follows is a review of the different parts of a scientific paper so that you can become familiar with the format and understand how to interpret the scientific papers you will read during the course.

Note that most journals use headers to indicate different sections of the paper, but occasionally the headers are missing. In those cases, you may have to discern what parts of the paper based on the kind of content in the section.

Notes on reading scientific papers: Don't worry too much if you don't know what every word means. Pause throughout your reading to write a note or jot down a question. Plan on reading sections over a few times and write down the major message in that section in your own words.

Title

An informative title begins every scientific paper. In the example pictured above, the title is: "Meta-analysis reveals declines in terrestrial but increases in freshwater insect abundance." This title hints at what the research question is and what the results are.

Authors and Affiliations

The people involved in the research are listed in the author line, including what institution or organization they are affiliated with.

Abstract

The abstract is a brief overview of the paper, summarized into a paragraph. The abstract is found at the beginning of the article and includes a brief description of the purpose, methods, results, and conclusions.

Introduction

The introduction of a scientific paper is especially important. It must outline the purpose of the research presented. This includes providing all the necessary background for understanding the context of the research, including a review of the relevant, published literature, the question of interest, and the broader societal or scientific relevance of the research. In other words, if you want to understand the why behind a scientific paper, then the introduction is where to look!

This section of the paper covers:

A. What is known from previous literature

B. What is not known

C. Objectives or purpose of study

D. Testable hypotheses associated with the objectives or purpose

Materials and Methods

This section illustrates the "how" of the research. It describes the evidence and procedures used to address the question. Below the first paragraph of the materials and methods of the example scientific paper used above. The materials and methods section is often quite detailed and lengthy. It must provide enough detail to permit another scientist to replicate the research. This section includes the methods used to gather data and the methods used to analyze the data.

This section of the paper covers:

A. The study system (location, organism, etc.,)

B. How the research was conducted

NOTE: In some journals, the Materials and Methods section can be found at the end of the article or is omitted from the article entirely and included only in online supplementary information.

Results

This section is a straightforward statement of the results. Typically, the results section refers to tables and figures that summarize findings in a visual format that best communicates the data. If the methods involved in understanding the evidence require statistical analyses, the statistical significance of the results are also outlined here. Importantly, there is no interpretation of the results in this section.

This section of the paper covers:

A. New findings (without interpretation)

B. Whether results from inferential tests are statistically significant

NOTE: In some journals, the Results and Discussion/Conclusions sections are combined can be found at the end of the article or is omitted from the article entirely and included only in online supplementary information.

Discussion/Conclusions

The Discussion, or Conclusions, section is the final section of the original research paper and summarizes the research. As with the introduction, this section must accomplish several things. First, the major results are summarized and interpreted. The findings are related to previous research on the subject, which would have been outlined in the introduction. The limitations of the research are discussed, and future directions for more research to address the question are outlined. Finally, the societal and scientific implications of the research are described in detail.

This section of the paper covers:

A. Reiteration of new findings with interpretation

B. Contextualization of the prior knowledge and hypotheses

C. Limitations

D. Future directions or new hypotheses that build upon this research

References/Literature Cited

In the References, or Literature Cited, section, the authors attribute evidence-based information and ideas to different sources of information. Throughout the text of the paper, sources are identified with in-text citations. This section provides identifying information for all of the in-text citations that support statements within the main body of the paper.

NOTE: Different journals request different reference formats. Some of the most commonly used are APA or MLA formats.

Dig Deeper!

See the "Anatomy of an Article" page via Arizona State University's "ask a Biologist" site, which describes how to read a scientific paper.
See how to "dissect" an article with an example from Arizona State University's "ask a Biologist" site.
Review the "Anatomy of a Research Paper" article.
Review the "Anatomy and physiology of a scientific paper" article.
"Primary, Secondary, and Tertiary Literature"
"The Real Process of Science"