Purpose
What does the methods section explain?
The materials and methods section explains how the investigation was performed and how evidence was collected. Its main purpose is reproducibility.
Another student or researcher should be able to understand the experimental design, identify the important variables, and repeat the procedure under comparable conditions.
Recommended structure
What to include in materials and methods
- Important materials and equipment
- Independent, dependent, and controlled variables
- Experimental conditions and quantities
- Procedure in logical order
- Measurement and recording methods
- Repeated trials and sample size
- Relevant safety precautions
Materials
Identify important equipment and substances
Include equipment and materials that affect how the experiment is performed or interpreted. Record useful specifications such as capacity, concentration, precision, or model when they matter.
Useful detail
Specific description
50 mL graduated cylinder with 1 mL divisions.
Too general
Unclear description
Measuring equipment.
Experimental design
Explain how variables were managed
- State how the independent variable was changed.
- Explain how the dependent variable was measured.
- Identify important controlled variables.
- Describe how controlled conditions were maintained.
- Include a control group or control treatment when relevant.
Procedure
Describe the process in logical order
Write the procedure in the sequence it was performed. Include quantities, times, temperatures, distances, concentrations, and other conditions needed to reproduce the investigation.
Clear method sentenceThe solution was heated to 40°C and maintained at that temperature for five minutes before the reaction was started.
Avoid vague phrases such as “some solution was heated” or “the results were measured.” State exactly what was measured and how.
Data collection
Explain how measurements were recorded
- Identify the instrument used for each measurement.
- Include measurement units and relevant precision.
- Explain when measurements were taken.
- State how qualitative observations were recorded.
- Describe any calculation used to process raw data.
Reliability
Document repeated trials
Repeated measurements help reveal variation and reduce the influence of isolated errors. State how many trials were performed and whether an average or other summary value was calculated.
Do not claim that repetition removes every source of error. Repeated trials mainly improve the reliability of measurements affected by random variation.
Safety
Include relevant precautions
Mention precautions that are directly connected to hazards in the investigation. Identify the hazard, the risk it creates, and the action used to reduce that risk.
Safety statement exampleSafety goggles were worn when handling the acid solution to reduce the risk of eye exposure from splashes.
Writing style
Use precise and objective language
- Describe completed actions in past tense.
- Use consistent scientific terminology.
- Report quantities with units.
- Avoid conversational instructions.
- Remove unnecessary routine actions.
- Do not interpret results in this section.
Common mistakes
Methods-section problems to avoid
- Leaving out quantities or measurement units.
- Using vague equipment descriptions.
- Failing to identify controlled variables.
- Writing steps in the wrong order.
- Omitting repeated trials.
- Including results or conclusions.
- Listing hazards without explaining precautions.
Related guides
Continue the lab report workflow
Review the scientific context in the Lab Report Introduction guide, or review the complete section order in the Lab Report Format guide.
Questions and answers
Materials and methods FAQ
What belongs in the materials and methods section?
It should identify important materials and equipment and explain the experimental procedure, measurements, variables, conditions, repeated trials, and relevant safety precautions.
Should the methods section be written in past tense?
Completed experimental actions are normally written in past tense because the section describes what was done.
How detailed should the procedure be?
It should contain enough relevant detail for another person to understand and reproduce the investigation without including unnecessary routine information.
Should results be included in the methods section?
No. The methods section explains how evidence was collected. Observations, measurements, and calculated outcomes belong in the results section.