How to Write a Scientific Report: IMRaD Structure Explained

The scientific report is the standard format for communicating research in natural sciences, social sciences, and related disciplines. IMRaD provides a consistent structure that helps readers find information quickly and allows reviewers to evaluate each aspect of the research separately.

Why IMRaD exists

IMRaD is not arbitrary — each section answers a specific question that readers need answered in order to evaluate the research:

Readers use this structure to navigate: a methods expert may read the Methods first to assess rigour; a busy academic may read only the Abstract and Discussion. The structure serves these diverse reading purposes.

Abstract

Write last. 150–250 words. Covers: background, objective, methods (briefly), main results, and conclusions/implications. Must be self-contained — no references, no unexplained abbreviations.

Example abstract structure:

"[Background: 1–2 sentences on the field/problem] [Objective: 1 sentence — what this study aimed to investigate] [Methods: 2–3 sentences — design, participants, key measures] [Results: 2–3 sentences — main findings with key numbers] [Conclusion: 1–2 sentences — interpretation and significance]"

Introduction

The Introduction builds from broad to narrow, ending with the research question or hypothesis:

Structure (the funnel model):

1. Background — The broad research area and its importance
2. Gap — What is not yet known or what is contested
3. Purpose — What this study aimed to investigate
4. Hypothesis (for experimental studies) — The specific prediction

Key principle: The Introduction should make the research question feel inevitable — the reader should understand why this specific question needed investigating.

Example Introduction structure:

"Spaced practice has been established as one of the most reliable methods for improving long-term memory retention in laboratory settings (Cepeda et al., 2006; Dunlosky et al., 2013). However, the majority of studies have used artificial materials (word lists, arbitrary facts) in single-session designs that do not reflect the complexity of real educational contexts [gap]. This study investigates whether the spacing advantage holds for secondary school biology content taught over a six-week period [purpose]. It was hypothesised that students receiving spaced retrieval practice would demonstrate significantly greater retention at a four-week delay than students receiving massed practice, as measured by free recall and multiple-choice tests [hypothesis]."

Methods

The Methods section must be detailed enough to allow replication. Write in past tense; passive voice is traditional but active is increasingly accepted.

Sub-sections:

Participants:

• Who participated? (demographic details relevant to the study)
• Recruitment method
• Inclusion/exclusion criteria
• Sample size and power analysis (for quantitative studies)
• Ethical approval and consent

Design:

• Research design (experimental, quasi-experimental, correlational, qualitative)
• Independent and dependent variables (for experiments)
• Between-subjects vs. within-subjects design
• Control conditions

Materials:

• Tests, questionnaires, stimuli, apparatus used
• Reference to established measures (with citation) or describe new instruments in detail

Procedure:

• Step-by-step account of data collection
• In what order did events happen?
• How were conditions assigned?

Data analysis:

• Statistical tests used and why
• Software used
• How were qualitative data analysed?

Results

The Results section presents data without interpretation. Interpretation belongs in the Discussion.

Principles:

• Report findings in order of importance or in the order questions/hypotheses were introduced
• Use clear paragraph structure: one main finding per paragraph
• Reference tables and figures in the text: "(see Table 1)"
• Report statistics fully: t(58) = 3.21, p = .002, d = 0.78
• Use past tense throughout

Common structure:

1. Descriptive statistics (means, standard deviations)
2. Main results (statistical tests, effect sizes)
3. Secondary or exploratory findings

Example Results paragraph:

"Retrieval practice produced significantly higher mean free recall scores at the four-week delay (M = 14.3, SD = 3.1) compared to the massed practice control condition (M = 9.7, SD = 3.4), t(58) = 5.12, p < .001, d = 1.31. This effect was consistent across both high-ability (top quartile) and low-ability (bottom quartile) groups (see Table 2), with no significant interaction between condition and ability level, F(1, 56) = 0.43, p = .51."

Discussion

The Discussion is the most intellectually demanding section. It interprets the results, connects them to the literature, addresses limitations, and draws conclusions.

Structure:

1. Restate the main finding (1–2 sentences, without statistics)
2. Interpret the finding — what mechanism explains it? What does it mean?
3. Connect to prior literature — how does this finding compare with previous work? Does it confirm, extend, or contradict?
4. Limitations — what are the constraints on the conclusions? What alternative explanations exist?
5. Implications — what follows from these findings? For practice, policy, or future research?
6. Conclusion — a brief final statement of the study's contribution

Common Discussion mistakes:

Restating results — The Discussion interprets; it does not repeat what the Results said with different words.

Overclaiming — Results sections say what was found; Discussion sections say what it means. The Discussion should be appropriately hedged: "these findings suggest" not "these findings prove."

Ignoring limitations — Every study has limitations. Naming them shows intellectual honesty and actually strengthens the Discussion by showing you understand the scope of your conclusions.

No connection to the literature — The Discussion should explicitly connect your findings to the sources cited in the Introduction, showing how your findings extend, confirm, or challenge prior work.

For citation formatting in Vancouver or APA style (common in sciences), see the Vancouver Referencing Guide and APA Referencing Guide. For lab reports specifically, see the Lab Report Writing Guide.