How to Structure the Introduction Section of Your Manuscript

The Introduction section is an important part of a manuscript. This section serves two main purposes. The first is to pique your reader’s interest. To do this, you want your Introduction to be direct, specific, and clear. You also want the text to be readable and as short as possible.

The second purpose of the Introduction is to be informative. You want to prepare readers, regardless of their background, to understand the paper.

To write an informative Introduction, follow the structure and guidelines below.

The Funnel

The Introduction has a fairly standard structure that is shaped like a funnel. The content starts broad and progressively narrows down to a question and hypothesis.

Paragraph 1 – Context and significance

Start your Introduction by giving your reader some background and context. Open with a sentence that introduces your reader to your field and gives them a big picture perspective. For example, if you study a gene linked to Alzheimer’s disease, you might start by describing the prevalence of this disease and its devastating impact on patients and their families. Or, if you are testing a new treatment for patients with colon cancer, you may want to start by describing the lack of effective treatments for the disease.

Then you want to start pointing toward your specific area of research within the broader field. If we think about the examples above, you might mention the value of genetic research in finding treatments for Alzheimer’s disease, or the need to develop more effective treatments for colon cancer. This approach will indicate the larger problem you aim to address with your work—the significance.

Paragraph 2+ – Rationale and relevance

After pointing toward your area of research, progressively narrow down to your specific area of interest. For example, you might introduce the gene you study and how that gene is linked to Alzheimer’s disease. Or you might introduce the type of treatment that you are developing and how that treatment might effectively treat cancer.

As you draft this paragraph (or two), you want to set the stage for what you set out to accomplish in your study. Describe what is known in your field, citing references and distinguishing your previous work from the work of others. Then lead your reader to what is unknown or what problem needs to be addressed. This approach will highlight the rationale and relevance of your work.

In this paragraph, include a clear statement that implies or states the importance of the work. You do not always need to clearly indicate the big picture importance of the work. For example, in basic research, adding new knowledge to the field is important enough.

Paragraph 3 – Question and approach

In the last paragraph of your Introduction, state the question you set out to answer. This question often takes the form of a hypothesis, objective, aim, or purpose statement.

Note that this question is the single most important statement in the Introduction section. The entire paper depends on this statement.

In some cases, you may also want to briefly introduce readers to your overall approach to answer the question. This information is most helpful if your approach is new, unusual, or complicated. It can also be helpful if you need to identify your study as a specific type (eg, retrospective, in vitro).

If you wish to include a few words about your methodology, such as the model system or study type you used, keep the details to a minimum. Detailed methods belong in the Materials and Methods section. To help you keep this information concise, you can often combine the question and approach in a single statement: “to determine X, we used Y approach.”

In this final paragraph, resist the temptation to summarize your findings, state your conclusions, or describe the overall significance of your completed work. You don’t want to give away the conclusions of your study before telling the story of your experiments (methods) and findings (results). This summary would be best placed at the beginning of your Discussion section.

When to Write the Introduction

When writing a manuscript, many authors believe that they need to start with the abstract or Introduction section. They think that they need to write the manuscript in the same order that readers will read it. But drafting your manuscript in a different order is more efficient and effective.

I recommend waiting to draft the Introduction until after you have written your Discussion section. After drafting the Discussion, you will have a better idea of the key points you want to make. You will know what background the reader will need to understand your research, including its context within your field and what others have shown. This information will help you more easily and efficiently draft the Introduction section.