Overview
What is the scientific method?
The scientific method is a structured approach to investigating questions using observations, controlled testing, measurements, analysis, and evidence-based conclusions.
It is not simply a rigid checklist. Scientists often revise earlier steps, repeat trials, improve methods, and develop new questions as evidence becomes available.
Complete process
Nine steps of the scientific method
Make an observation
Identify a pattern, problem, event, or relationship that can be investigated scientifically.
Research the topic
Review reliable background information, relevant scientific principles, and previous findings.
Ask a testable question
Write a focused question that identifies what will be changed, measured, or compared.
Develop a hypothesis
Predict the expected relationship between variables and support the prediction with scientific reasoning.
Design the experiment
Plan variables, controls, materials, measurements, repeated trials, and safety precautions.
Collect data
Record quantitative measurements and qualitative observations accurately and consistently.
Analyze the results
Use tables, graphs, calculations, averages, patterns, and anomalies to evaluate the evidence.
Draw a conclusion
Answer the research question and decide whether the evidence supports the hypothesis.
Communicate and improve
Report the findings, identify limitations, and refine the investigation when additional testing is needed.
Observation
Begin with something measurable
A useful scientific observation identifies something that can be described, compared, measured, or tested. It may come from laboratory work, field study, previous research, or an unexpected result.
Observation exampleSugar appears to dissolve faster in warm water than in cold water.
Research question
Turn the observation into a testable question
The question should identify the experimental system and the variables being investigated. Avoid questions that are too broad, subjective, or impossible to measure.
Testable questionHow does water temperature affect the time required for a fixed mass of sugar to dissolve?
Hypothesis
Make a scientific prediction
A hypothesis predicts the expected relationship between the independent and dependent variables and explains the scientific reasoning behind that prediction.
Hypothesis structureIf [independent variable changes], then [dependent variable will change], because [scientific reason].
Experiment
Design a fair and repeatable test
- Change one independent variable deliberately.
- Measure the dependent variable consistently.
- Keep important controlled variables constant.
- Include a control group when appropriate.
- Perform repeated trials.
- Use suitable measurement instruments and units.
- Address relevant safety risks.
Evidence
Collect quantitative and qualitative data
Quantitative data
Numerical measurements
Time, mass, temperature, volume, distance, and concentration are examples of quantitative data.
Qualitative data
Descriptive observations
Color change, gas formation, texture, appearance, and behavior are examples of qualitative data.
Analysis
Evaluate patterns and variation
Organize data into tables and graphs, calculate useful values, compare repeated trials, identify anomalies, and determine whether the evidence shows a consistent relationship.
- Calculate averages when appropriate.
- Compare experimental and accepted values.
- Use consistent units and significant figures.
- Identify trends, differences, and anomalies.
- Consider measurement uncertainty.
Conclusion
Answer the question using evidence
The conclusion should state the main finding, cite relevant evidence, and explain whether the hypothesis was supported, partially supported, or not supported.
Scientists do not normally claim that one experiment proves a hypothesis. Conclusions are limited to the evidence and conditions tested.
Scientific cycle
Repeat, revise, and investigate further
Results may lead to a revised hypothesis, improved procedure, additional trials, or a new research question. This repeated process is a normal and valuable part of science.
Investigation cycleObserve → question → test → analyze → conclude → revise
Common mistakes
Scientific-method problems to avoid
- Using a question that cannot be tested.
- Changing multiple variables at the same time.
- Performing only one trial.
- Recording measurements without units.
- Ignoring anomalous results.
- Claiming the hypothesis was proven.
- Drawing conclusions not supported by the data.
Related resources
Document and analyze the investigation
Organize the complete investigation using the Lab Report Template, and evaluate experimental accuracy with the Percent Error Calculator.
Questions and answers
Scientific method FAQ
What are the main steps of the scientific method?
The main steps are observation, background research, research question, hypothesis, experiment, data collection, analysis, conclusion, and communication.
Does the scientific method always follow one fixed order?
The process is structured, but scientists may return to earlier steps, revise a hypothesis, improve a method, or repeat an experiment when new evidence appears.
What happens if a hypothesis is not supported?
An unsupported hypothesis is still useful because it helps refine the scientific explanation, improve the experiment, or generate a new testable prediction.
Why must experiments be repeated?
Repeated trials help reveal variation, improve reliability, and reduce the influence of isolated random errors.