4 Step approach to writing the Introduction section of a research paper

If you want others to cite your paper, you should make sure they read it first. Let us assume that the title and the abstract of your paper have convinced your peers that they should see your paper. It is then the job of the Introduction section to ensure that they start reading it and keep reading it, to pull them in and to show them around as it were, guiding them to the other parts of the paper (Methods, Results, Discussion, and Conclusion).

This article tells you, with examples, what you should include in the Introduction and what you should leave out, and what reviewers and journal editors look for in this section.

What is the function of the Introduction section?

Put simply, the Introduction should answer the question ‘Why:’ why you choose that topic for research; why it is important; why you adopted a particular method or approach; and so on. You can also think of the Introduction as the section that points out the gap in knowledge that the rest of the paper will fill, or the section in which you define and claim your territory within the broad area of research.

The other job the Introduction should do is to give some background information and set the context. You can do this by describing the research problem you considered or the research question you asked (in the main body of the paper, you will offer the solution to the problem or the answer to the question) and by briefly reviewing any other solutions or approaches that have been tried in the past.

Remember that a thesis or a dissertation usually has a separate chapter titled ‘Review of literature,’ but a research paper has no such section; instead, the Introduction includes a review in brief.

Now that you have given the background and set the context, the last part of the Introduction should specify the objectives of the experiment or analysis of the study described in the paper. This concluding part of the Introduction should include specific details or the exact question(s) to be answered later in the paper.

The 4-step approach to writing the Introduction section 

As a rule of thumb, this section accounts for about 10% of the total word count of the body of a typical research paper, or about 400 words spread over three paragraphs in a 4000-word paper.¹ With that, let us now understand how to write the Introduction section step-by-step:

1. Provide background information and set the context.

This initial part of the Introduction prepares the readers for more detailed and specific information that is given later. The first couple of sentences are typically broad.

Below are some examples:

• A paper on organic matter in soil can begin thus: ‘Sustainable crop production is a function of the physical, chemical, and biological properties of soil, which, in turn, are markedly affected by the organic matter in soil.’
• A paper that discusses the possible beneficial role of bacteria in treating cancer can begin as follows: ‘The role of bacteria as anticancer agent was recognized almost hundred years back.’
• A paper on lithium batteries can introduce the study with the following sentence: ‘The rapid growth of lithium ion batteries and their new uses, such as powering electric cars and storing electricity for grid supply, demands more reliable methods to understand and predict battery performance and life.’

At the same time, the introductory statement should not be too broad: note that in the examples above, the Introduction did not begin by talking about agriculture, cancer, or batteries in general, but by mentioning organic matter in soil, the role of bacteria, and lithium ion batteries.

Once the first sentence has introduced the broad field, the next sentence can point to the specific area within that broad field. As you may have noticed, the papers in the examples mentioned above introduced the subfield by mentioning 1) remission of some types cancer following accidental infection by Streptococcus pyogenes, 2) organic matter in soil as a source of nutrients for plants and of energy for microorganisms, and 3) imaging techniques to visualize the 3-dimensional structure of the materials and components of batteries on nanoscale.

2. Introduce the specific topic of your research and explain why it is important.

As you can see from the above examples, the authors are moving toward presenting the specific topic of their research. So now in the following part, you can bring in some statistics to show the importance of the topic or the seriousness of the problem.

Here are some examples:

• A paper on controlling malaria by preventive measures, can mention the number of people affected, the number of person-hours lost, or the cost of treating the disease.
• A paper on developing crops that require little water can mention the frequency of severe droughts or the decrease in crop production because of droughts.
• A paper on more efficient methods of public transport can mention the extent of air pollution due to exhausts from cars and two-wheelers or the shrinking ratio between the number of automobiles and road length.

Another way to emphasize the importance of the research topic is to highlight the possible benefits from solving the problem or from finding an answer to the question: possible savings, greater production, longer-lasting devices, and so on. This approach emphasizes the positive.

For example, instead of saying that X dollars are lost because of malaria every year, say that X dollars can be saved annually if malaria is prevented, or X millions litres of water can be saved by dispensing with irrigation, or X person-hours can be saved in the form of avoided illnesses because of improved air quality or reduced pollution.

3. Mention past attempts to solve the research problem or to answer the research question.

As mentioned earlier, a formal review of literature is out of place in the Introduction section of a research paper; however, it is appropriate to indicate any earlier relevant research and clarify how your research differs from those attempts. The differences can be simple: you may have repeated the same set of experiments but with a different organism, or elaborated (involving perhaps more sophisticated or advanced analytical instruments) the study with a much larger and diverse sample, or a widely different geographical setting.

Here are two examples:

• ‘Although these studies were valuable, they were undertaken when the draft genome sequence had not been available and therefore provide little information on the evolutionary and regulatory mechanisms.’
• ‘Plant response is altered by insect colonization and behaviour but these aspects have been studied mostly in sole crops, whereas the present paper examines the relationship between crops and their pests in an intercropping system.’

4. Conclude the Introduction by mentioning the specific objectives of your research.

The earlier paragraphs should lead logically to specific objectives of your study. Note that this part of the Introduction gives specific details: for instance, the earlier part of the Introduction may mention the importance of controlling malaria whereas the concluding part will specify what methods of control were used and how they were evaluated. At the same time, avoid too much detail because those belong to the Materials and Methods section of the paper.

If, for example, your research was about finding the right proportions of two metals in an alloy and you tested ten different proportions, you do not have to list all the ten proportions: it is enough to say that the proportions varied from 50:50 to 10:90.

Here are two more examples:

• ‘We aimed to assess the effectiveness of four disinfection strategies on hospital-wide incidence of multidrug-resistant organisms and Clostridium difficile’
• ‘We aimed (1) to assess the epidemiological changes before and after the upsurge of scarlet fever in China in 2011; (2) to explore the reasons for the upsurge and the epidemiological factors that contributed to it; and (3) to assess how these factors could be managed to prevent future epidemics.’

There are different ways of constructing the objectives. Using questions², hypotheses, and infinitives are the more common constructions (both examples in the previous paragraph use infinitives), each of which is illustrated below with some fictitious text:

Questions

• ‘Do some genes in wheat form gene networks? If they do, to what extent as compared to rice?’
• ‘Do the regulatory elements in the promoters of those genes display any conserved motifs?’
• ‘Finally, and more specifically, do those genes in wheat display any tissue- or organ-specific expression pattern?’

Hypotheses

‘We decided to test the following four hypotheses related to employees of information-technology companies:

H1: Career stages influence work values.

H2: Career stages influence the level of job satisfaction.

H3: Career stages do not influence organizational commitment.’

Using infinitives

‘To examine the response of Oryza sativa to four different doses of nitrogen in terms of 1) biomass production, 2) plant height, and 3) crop duration.’

Compared to two other sections of a typical research paper, namely Methods and Results, Introduction and Discussion are more difficult to write. However, the 4-step approach described in this article should ease the task.

A final tip: although the Introduction is the first section of the main text of your paper, you don’t have to write that section first. You can write it, or at least revise it, after you have written the rest of the paper: this will make the Introduction not only easier to write but also more compelling.

To learn in more detail the guidelines to write a great Introduction section, check out this course: How to write a strong introduction for your research paper

References:

1. Araújo C G. 2014. Detailing the writing of scientific manuscripts: 25-30 paragraphs. Arquivos Brasileiros de Cardiologia 102 (2): e21–e23

2. Boxman R and Boxman E. 2017. Communicating Science: a practical guide for engineers and physical scientists, pp. 7–9. Singapore: World Scientific. 276 pp.

Related reading:

• The secret to writing the introduction and methods section of a manuscript
• Tips for writing the perfect IMRAD manuscript