Community Blog

Keep up-to-date on postgraduate related issues with our quick reads written by students, postdocs, professors and industry leaders.

Abstract vs Introduction – Differences Explained

Dr Harry Hothi
Abstract vs Introduction

Any academic write up of a research study or project will require the inclusion of an abstract and introduction. If you pick up any example of a research paper for a journal, dissertation for a Masters degree or a PhD thesis, you’ll see the abstract, followed by the introduction. At first glance you’ll notice that the abstract is much shorter in length, typically a quarter or third of a page of A4. The introduction on the other hand is longer, taking up at least an entire page of writing.

Beyond the length, what are the differences in the content of the two sections? In short, the abstract is a summary of the entire study, describing the context, research aim, methods, results and key conclusions. The introduction gives more detail on the background of the subject area, the motivation for the study and states the aims and objectives.

Read on to learn more.

What is an Abstract?

The main purpose of an abstract is to succinctly give the reader an overview of why the study was needed, what the purpose of the project was, the research question, the key materials and methods that were used, the main results and what conclusions were drawn from this. Many abstracts also conclude with a sentence on the significance or impact of the research. These are sometimes also referred to as an executive summary.

The reader should have an understanding of the paper topic and what the study was about from the abstract alone. He or she can then decide if they want to read the paper or thesis in more detail.

Abstracts are particularly useful for researchers performing a literature review, which involves critically evaluating a large number of papers. Reading the abstract enables them to quickly ascertain the key points of a paper, helping them identify which ones to read in full.

Abstracts are also very important for learning more about the work performed in papers that are hidden behind academic journal paywalls (i.e. those that are not open access). Abstracts are always made freely available, allowing a researcher to understand the context and main point of the work and then decide if it’s worth paying to read the entire paper. These are sometimes referred to as the ‘de facto introduction’ to the research work as it’s usually the first section people read about your study, after the title page.

How do you Write an Abstract?

The majority of academic journals place a limit of 250 words on the length of the abstract in papers submitted to them. They do this to ensure you give a quick overview of only the most important information from your study, helping the reader decide if they want to read the whole paper too. Make sure you double check the specific requirements of your target journal before you start writing.

Universities or other academic institutions often allow up to 500 words for an abstract written for a doctoral thesis.

Abstracts can be either structured or unstructured in the way they are formatted. A structured abstract contains separate headings to guide the reader through the study. Virtually all STEM journals will require this format be used for a researcharticle. The exact names used for each heading can differ but generally there are defined as:

  1. Background. This is also sometimes called the Introduction. This section should give an overview of what is currently known about the research topic and what the gap in knowledge is. The reader should understand the problem your research will address; i.e. what was your study needed. Don’t include any references or citations in the abstract.
  2. Aim and Objective. Give a brief explanation of what the study intended to achieve and state the research question or questions that you proposed. Some authors also include the hypothesis here too.
  3. Materials and Methods. Use the methods section to describe what you investigated, what the study design was and how you carried it out.
  4. Results. Give an overview of your key findings.
  5. Discussion and Conclusion. Some journals may ask for these two terms to be used as separated headings. These sections explain why you may have obtained the results that you did, what this means and what the significance or impact of this might be.

An informative abstract should provide a concise summary of all the important points in your research project, including what the central question relating to the subject matter was. Make it interesting to read too; this may be the difference between your abstract being accepted or rejected if you decide to submit it to an upcoming conference. Reviewers for large conferences often have to read hundreds of abstracts so make sure yours stands out by being easy to read and follow.

It’s less common that you’ll be asked to write an unstructured abstract. If you are, however, be aware that the key difference is that an unstructured abstract does not include separate headings. The flow of the abstract text should still follow the 5 points listed above but they should all be written within one long paragraph.

What is the Introduction?

The introduction section is the first main written work presented after the abstract in your paper manuscript or thesis. In a research paper, the introduction will be followed by a section on the materials and methods. In thesis writing, the introduction will be followed by the literature review.

The main aim of introduction writing is to give the reader more detail on the background information of the study. It should include a brief description of the key current knowledge that exists based on the work presented in previous literature and where the gaps in knowledge are. The introduction should convey why your research was needed in order to add new understanding to your subject area. Make sure that you reference all the publications that you refer to.

When writing an introduction for a scientific paper you should also include the aim of your study and the research objectives/questions. If relevant, also include your hypothesis or (null hypothesis).

How do you Structure the Introduction?

The general rule of thumb for a research paper is to use size 12 Times New Roman font, double spaced. Write four separate paragraphs which together are no longer than one page in length. Structure the four paragraphs as follows:

  1. Set the context of the research study, giving background information about the subject area.
  2. Describe what is currently know from previously published work and what is poorly understood – i.e. the research gap.
  3. Explain how addressing this gap in knowledge is important for your research field – i.e. why this study is needed.
  4. Give a broad overview of the aims, objectives and hypothesis of the study.

You should not describe the research method used in this section nor any results and conclusions.


You should be clear now on what the differences between an abstract vs introduction are. The best way to improve your academic writing skills for these are to read other examples from other research articles and start writing!

What is Tenure Track?
What Is Tenure Track?

Tenure is a permanent position awarded to professors showing excellence in research and teaching. Find out more about the competitive position!

Read More »



Join thousands of other students and stay up to date with the latest PhD programmes, funding opportunities and advice.

Browse PhDs Now

Other Posts
Dr Malika Grayson

Dr Grayson gained her PhD in Mechanical Engineering from Cornell University in 2016. She now works in industry as an Applications Portfolio Manager and is a STEM Speaker and Advocate.

Read More »
Dr Zoë Ayres

Dr Ayres completed her PhD at the University of Warwick in 2017, researching the use of diamond to make electrochemical sensors. She is now a research scientists in the water industry, developing different analytical techniques and sensors to help keep our water systems safe.

Read More »

Browse PhDs Now

Join Thousands of Students

Join thousands of other students and stay up to date with the latest PhD programmes, funding opportunities and advice.

Verified by MonsterInsights