IMRaD is the standard structure of a scientific article and an empirical thesis. It divides the text into four parts: Introduction, Methods, Results and Discussion. The acronym comes from the first letters of those four section names. The logic is simple and stays the same every time: the introduction says why and what you are studying, the methods say how you studied it, the results say what you found, and the discussion says what it means. This predictability is exactly why IMRaD is the most widely used format in scientific publishing.
What the acronym IMRaD stands for
IMRaD is an acronym built from four words that name the core chapters of a research text:
- I - Introduction: defines the problem, the aim, and the research questions or hypotheses
- M - Methods: describes how you carried out the research and how it can be repeated
- R - Results: presents the findings and data, without interpreting them
- a - and: a connective added to the acronym only so it can be pronounced
- D - Discussion: interprets the results and places them within wider knowledge
The lowercase „a" in the middle of the acronym has no chapter of its own. It is there only so the acronym can be pronounced comfortably, which is why you will often see it written in lowercase: IMRaD. You may also come across the extended version IMRaDC or IMRaD/C, where the final „C" marks the Conclusion as a separate section.
In a thesis or dissertation, these four parts correspond to the introduction, methodology (or methods), results, and discussion. It pays to use the terminology consistently, because your supervisor and examiners expect it in its established form.
Why IMRaD emerged and where it is used
IMRaD emerged in response to the need to standardise the way scientists report their research. The first scientific journals in the 17th century published findings as descriptive letters and narratives, with no fixed structure. Readers had to search each article anew to find where the author described the procedure and where the results were.
The seed of today's structure is credited to Louis Pasteur and his work Études sur la Bière from 1876, in which he separated the description of the procedure from the findings. The format was later popularised by the British statistician Sir Austin Bradford Hill, who worked with the British Medical Research Council. IMRaD settled into a binding standard for presenting scientific work in the 1970s, when it was captured by the American standard ANSI Z39.16 (issued in 1972 and revised in 1979).
According to a review study by Luciana Sollaci and Mauricio Pereira that mapped fifty years of the format's use (PubMed, 2004), IMRaD began to take hold in medical journals in the 1940s, reached roughly 80 percent usage in the 1970s, and in the 1980s became practically the only format for original research articles.
Today IMRaD dominates above all in these areas:
- Scientific articles of original research in academic journals
- Empirical biomedicine and public health, where it was born
- Natural and social sciences, engineering and computer science
- Empirical theses and dissertations with their own data collection and analysis
By contrast, in purely theoretical, review, or historical work, IMRaD is used rarely, because such texts have no separate methods and results chapter in the sense the format assumes.
What belongs in each of the four parts
The strength of IMRaD is that each part has one clear job and does not overlap with the others. Once you know what goes where, the text is easier to write and clearer to read.
Introduction
The introduction places the topic in context and says what and why you are studying. It explains the problem that motivates the work, names the gap in knowledge, and leads into a concrete aim and research questions or hypotheses. The introduction is written from the wider to the narrower: from context, through justification, to a precisely formulated aim.
Methods
The methods section explains how you arrived at the results. It is a set of instructions by which another researcher could repeat and verify your work. It covers the research design (quantitative, qualitative, or mixed), the way data were collected, a description of the sample, and the analysis procedure. It is usually written in the past tense, because it describes a procedure already carried out.
Results
The results present what you found, and nothing more. Here you give the data, tables, and charts, but you do not yet interpret them. The aim is for the reader to see the findings in their raw form and to form an opinion before your interpretation arrives. Separating the results from their interpretation is one of the main hallmarks of a good IMRaD text.
Discussion
The discussion answers the question of what the results mean. It interprets the findings, compares them with what the literature reports, explains both agreements and contradictions, and names the limitations of the research. It is in the discussion that the results connect back to the aim from the introduction, so the text closes the loop. Many journals include the conclusion within the discussion, while others split it into a separate section.
| IMRaD part | The question it answers | Tense and form |
|---|---|---|
| Introduction | Why and what am I studying? | present tense, context and aim |
| Methods | How did I study it? | past tense, description of procedure |
| Results | What did I find? | past tense, data without interpretation |
| Discussion | What does it mean? | interpretation, comparison with literature |
How IMRaD relates to the classic thesis structure
A classic thesis is usually divided into a theoretical part and a practical (analytical) part. IMRaD is a different way of organising the same content, one that puts the emphasis on your own research. These are not two incompatible worlds, but rather two views of the same text.
The main difference lies in where the theory goes. In the classic structure, the theoretical part forms a separate and often extensive chapter before the practical part. In a pure IMRaD format, the literature review is pulled into the introduction and the discussion, and no standalone „theory chapter" is written. This is precisely why IMRaD is more typical of scientific articles, which face strict length limits, than of long theses and dissertations.
| Element | Classic thesis structure | IMRaD |
|---|---|---|
| Theory | separate theoretical part | pulled into introduction and discussion |
| Own research | practical or analytical part | methods and results |
| Interpretation | results and discussion, conclusion | discussion (sometimes conclusion too) |
| Typical use | bachelor's and master's theses | scientific articles, empirical work |
In practice, many empirical theses combine both approaches. They have a theoretical part in the classic sense and a practical part arranged according to IMRaD logic: first methodology, then results, then discussion. That way you get the best of both worlds, a firm conceptual framework and a clear presentation of the research. The detailed breakdown of the whole thesis into title page, abstract, chapters, and appendices is covered in a separate article on how to structure a thesis.
When to use IMRaD and when not to
IMRaD is not a universal template for every piece of work. Its suitability depends on whether the text contains its own empirical research.
IMRaD is a good fit when:
- you are writing a scientific article of original research for an academic journal
- your work includes your own data collection (a survey, experiment, interviews, measurements)
- you want the procedure to be unambiguously verifiable and repeatable
- the field or journal prescribes IMRaD directly
IMRaD is not a good fit when:
- the work is purely theoretical or a review, with no research of its own
- it is a historical, legal-analytical, or philosophical piece that does not work with data
- your faculty prescribes a different binding structure
- the text is an essay, a case report, or another genre with its own established form
The deciding factor is always your faculty's methodological guidance. If the guidelines prescribe a specific chapter layout, it takes priority over general recommendations, IMRaD included. When choosing between approaches, it also helps to have thought through your research methodology, because it is the methodology that determines whether a separate methods and results chapter is needed at all.
What advantages IMRaD offers for readability
The main advantage of IMRaD is predictability. When every article is arranged the same way, the reader knows exactly where to find what they are looking for and does not have to read the whole text from the start.
- Fast orientation. A reviewer or expert reader can jump straight to the methods or results without hunting for them.
- A clear split between facts and interpretation. The results present the data; the discussion interprets it. The reader can tell what is a finding and what is the author's opinion.
- Verifiability. A separate methods chapter makes it possible to judge whether the conclusions are supported and whether the research can be repeated.
- A logical arc. The introduction poses a question; the discussion answers it. The text holds together and has a clear beginning and end.
These qualities also explain why IMRaD became the standard in science specifically, where verifiability and clarity matter more than narrative style. What holds for a scientific article can be used in a thesis too: even when you write a classic theoretical-practical thesis, separating the results from their interpretation in the discussion section will increase its clarity and credibility.
If you are not sure which format suits your work, or you need help arranging the empirical part, our authors will advise you. Take a look at our services or write to us via contact and we will propose an approach tailored to your topic.
Frequently asked questions
What exactly does the acronym IMRaD stand for?
IMRaD stands for Introduction, Methods, Results and Discussion. These are the four core parts of a scientific article. The lowercase „a" in the middle is just the connective „and", which is added for pronunciation and has no chapter of its own.
Is IMRaD the same as the classic thesis structure?
No. A classic thesis is divided into a theoretical and a practical part, whereas IMRaD pulls the theory into the introduction and discussion and emphasises the methods and results. Many empirical theses combine both approaches: they have a theoretical part as well as a practical part arranged according to IMRaD.
Do I have to use IMRaD in my bachelor's or master's thesis?
Only if your faculty prescribes it, or if your work has its own empirical research that this structure suits. For purely theoretical and review work, IMRaD is not appropriate. Always follow your faculty's methodological guidance, which takes priority over general advice.
Does the conclusion belong in the IMRaD structure?
The conclusion can be part of the discussion, or form a separate section. Some journals use the extended version IMRaDC, where the final „C" marks the Conclusion. It depends on the tradition of the field and on the guidelines that apply to your work.
What is the difference between results and discussion in IMRaD?
The results present the findings and data without interpretation; the discussion interprets them and compares them with the literature. This separation is at the heart of IMRaD: the reader first sees the raw findings and only then your interpretation, so they can form their own opinion.
When did IMRaD emerge?
The seed of the format is credited to Louis Pasteur and his 1876 work; it was popularised by the statistician Austin Bradford Hill, and it settled into a standard in the 1970s (ANSI Z39.16, 1972). In medical journals it became the prevailing format in the 1970s and 1980s.