What is the IMRaD structure?

IMRaD stands for Introduction, Methods, Results, and Discussion — the standard structure for scientific lab reports. It is usually preceded by a title and abstract and followed by references.

What tense should a lab report be written in?

Use past tense for what you did and found (the methods and results), since the work is complete, and present tense for established facts and general truths in the introduction and discussion.

What is the difference between results and discussion?

The results section reports what you found, objectively and without interpretation, using figures and tables. The discussion interprets those results — what they mean, how they compare to expectations, their limitations, and their implications.

How to Write a Lab Report: IMRaD Structure & Example

A lab report communicates an experiment clearly enough that someone could understand, evaluate, and repeat it. Most follow the IMRaD structure — Introduction, Methods, Results, and Discussion — usually with a title and abstract at the front and references at the end. Here's what each part needs.

Title and abstract

The title should state precisely what was investigated. The abstract is a 150–250 word summary written last: the aim, method, key result, and main conclusion — no references or detail, just the essentials.

1. Introduction

State the background, the scientific question, and your hypothesis. Move from general context to the specific aim of this experiment. Briefly mention relevant theory and end with a clear hypothesis or objective.

2. Methods

Describe what you did in enough detail that the experiment could be replicated — materials, procedure, equipment, and any controls. Write in the past tense and usually the passive voice ("The solution was heated to 60 °C"). Do not write it as a numbered instruction list unless your brief asks for one.

3. Results

Report what you found — objectively and without interpretation. Present data in clearly labelled figures and tables, and refer to each in the text ("As shown in Figure 1…"). State key values and trends; save the "why" for the discussion.

Results vs. discussion — the key distinction:

Results: "Reaction rate increased from 0.2 to 0.8 mol/s as temperature rose from 20 °C to 60 °C (Figure 1)."

Discussion: "The increase in reaction rate with temperature is consistent with collision theory, as higher kinetic energy raises the frequency of effective collisions."

4. Discussion

Interpret your results. Explain what they mean, whether they support your hypothesis, how they compare to expected values or published work, and what the sources of error and limitations were. End by noting implications or improvements for future work.

5. Conclusion and references

State, briefly, what the experiment showed in relation to the aim. Then list every source you cited in the required style (often a numbered or author–date system — check your brief).

Formatting tips that earn easy marks

Number and caption every figure and table; refer to each in the text.
Report units and significant figures consistently.
Use past tense for what you did and found; present tense for established facts.
Keep results objective; keep interpretation in the discussion.
Write the abstract last.

Common mistakes

Mixing interpretation into the results section.
Methods too vague to replicate.
Figures with no labels, units, or captions.
Ignoring sources of error and limitations.
An abstract written first and never updated.

Frequently asked questions

What is IMRaD?

Introduction, Methods, Results, and Discussion — the standard lab report structure, usually with a title and abstract first and references last.

What tense should I use?

Past tense for what you did and found; present tense for established facts in the introduction and discussion.

What's the difference between results and discussion?

Results report findings objectively with figures and tables; the discussion interprets them — meaning, comparison, limitations, implications.

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How to Write a Lab Report (IMRaD)