How do you find the right balance between clarity, depth, and engagement in the introduction of a scientific paper to make the topic easy to understand, provide enough background without overwhelming the reader, and capture interest from the start?

This is no easy feat, but it is achievable with the right tips and information. This post explores the best practices for writing introductions in scientific papers, based on the paper “How to Write the Introduction to a Scientific Paper.”

• Importance of an Introduction
• Principles of writing a good introduction
• Models of writing an introduction
• Length 
• Number of references
• Other points to consider

Importance of an Introduction

The introduction of a scientific paper introduces the reader to the topic and explains its relevance and importance in the context of ongoing global research. A strong introduction engages the reader and sets the tone for the rest of the paper. 

Principles of writing a good introduction

A good introduction “sells” the article to editors, reviewers, and readers. It should contain:

• The known – Scientific background (supported by citations)
• The unknown – Gaps in existing knowledge 
• Research hypothesis or question – What your study aims to address
• Methodologies used – The approaches or techniques used in your study 

Models of writing an introduction

1- The problem-solving model

First introduced by Swales et al. in 1979, this model suggests that writers should identify the research problem, propose a solution, and discuss criteria for evaluating the issue.

2- The CARS model (Creating a Research Space)

This model includes three main steps:

• Establishing a territory (situation)
• Establishing a niche (problem)
• Occupying a niche (the solution)

A fourth step, a conclusion, can also be added to this model. The conclusion or summary is sometimes included to tie the introduction to the broader research context.

Establishing a territory 

When establishing a territory, the aim is to introduce the general topic and provide relevant background information. This includes a brief overview of the existing literature on the topic and an emphasis on the need for the current study. 

Establishing a niche

Establishing a niche means explaining the importance of the problem, presenting global and national data, and evaluating the current situation by highlighting the pros and cons. It also requires identifying gaps in existing knowledge, emphasising the significance of the proposed research, and explaining how it addresses these gaps. 

In addition, the research problem or question should be clearly formulated and the hypotheses briefly mentioned. 

The introduction of a scientific paper should follow an inverted pyramid structure, starting with broad background information before focusing on the specific research topic.

Occupying a niche

This is the third part of the introduction, in which the research rationale and the research question are presented in detail. Without this part, reviewers may not fully understand the purpose of the study, which is a common reason for rejection. 

Recommended length for an introduction

The length of the introduction may vary depending on the specific guidelines, so be sure to follow them. However, here are some general recommendations: For a project protocol, the introduction is usually about 1–2 pages long. For a thesis, it is typically 3–5 pages (double-spaced). For a scientific paper, the introduction is usually less than 10–15% of the total length of the manuscript.

See also: How to make your writing more readable for academic success

Recommended number of references in an introduction

While there are no strict rules, it is generally recommended that the introduction of a scientific paper contain four or five references, or, at most, one-third of the total references in the manuscript. However, the exact number depends on the type of paper and the subject area and should be checked in the guidelines. Also, make sure that the references are from reputable journals with a high impact factor to support the credibility of your work.  

Additional tip

According to Springer, your citations should fulfill the following criteria:

Balanced: If previous studies have reported conflicting results, you should ensure that you cite research that supports both points of view. 

Current: While citation timelines vary by discipline, you should include references published within the last 10 years whenever possible. However, be sure to cite the original discovery or first mention in the literature, even if it is older than 10 years. 

Relevant: The most important factor is relevance—the studies cited should be directly related to your research question.

Other points to consider

Keep in mind that the introduction should be written in clear and simple sentences in the present tense. In addition, it is important to introduce key terms, as they may need to be abbreviated for later use. 

Bottom line  

To write an effective introduction for a scientific paper, a balance must be struck between clarity, depth, and engagement. Using models such as the problem-solving model and the CARS model, researchers can introduce the topic, identify gaps in knowledge, and state the research problem and objectives.

Providing relevant background information, citing recent references, and emphasising the importance of the research attracts the reader’s attention and sets the tone of the paper. 

Need help with your academic writing? 

To improve the overall quality of your work, it is advisable to use advanced editing tools that respect the principles of originality and authorship. InstaText is one such tool that improves readability, style, grammar, and much more. It uses advanced language technologies—with the exception of generative AI, which is not allowed in academic writing. 

InstaText is compatible with various platforms, including Overleaf, the popular editor for LaTeX documents. If you already use InstaText, you can learn more about this option here.

If not, you can try InstaText for free and find out how it can help you refine your texts while maintaining academic integrity.

“InstaText is a great tool! I use it to improve English texts such as articles, projects and abstracts for conferences. The tool provides very useful suggestions that help me to translate the text to a professional level so that no additional review by “native speakers” is required. The time and money savings are obvious. I highly recommend it!”

— Dr. Janez Konc, Senior Researcher

“I am a translator and proofreader by profession and have tried many editing tools. It’s not an exaggeration to say that all the other apps I’ve used so far don’t come close to InstaText. It is literally innovative and revolutionary and has taken the editing game to a new level, leaving other competitors in the dust.”

— Dr. Ghodrat Hassani, Researcher in Translation Studies

“I can hardly imagine writing articles without InstaText. When I read through the proposed improvements, I immediately understand how the text should sound. It’s like a proofreader you can access at any time.”

— Dr. Jana Krivec, Senior Lecturer