Science is a way of asking questions about the world and using evidence to build better explanations.
You may have heard of the scientific method as a series of steps. A step by step model is useful when you are learning how investigations work, but real science is not always a perfectly straight path.
Scientists may return to an earlier question, change a hypothesis, collect more evidence, improve an investigation or try a different approach when new information appears.
This guide introduces a simple beginner model that can help you understand the main parts of a scientific investigation.
Science is based on questions and evidence
Scientific investigations often begin when someone notices something interesting and wants to understand it better.
A scientist may ask why something happens, how two things are related or what will happen when one condition changes.
The investigation then uses observations, measurements, tests or other evidence to examine the question.
The important idea is that scientific explanations should connect to evidence rather than depend only on opinion or expectation.
There is not one rigid recipe for all science
A classroom diagram may show the scientific method as a straight sequence.
That can be useful for learning, but different sciences investigate different kinds of questions.
An astronomer cannot place another star in a laboratory. A climate scientist cannot create a second Earth for comparison. Other scientists may perform controlled experiments, study existing records, build models or observe natural events.
Scientists can therefore use different approaches while still sharing important practices such as asking questions, collecting evidence, analyzing information, constructing explanations and communicating results.
A useful beginner model
For a simple investigation, you can think about the process in eight stages:
- Observe and wonder.
- Ask a testable question.
- Learn what is already known.
- Develop a hypothesis.
- Plan and carry out an investigation.
- Analyze the data.
- Draw a conclusion.
- Communicate the results and decide what to investigate next.
These stages help organize your thinking. They do not mean that you can never return to an earlier stage.
Step 1: Observe and wonder
Scientific thinking often starts with observation.
An observation is something you notice using your senses or a measuring tool.
For example, imagine that you are testing paper airplanes.
You notice that two airplanes made from the same sheet size sometimes travel different distances.
That observation can lead to curiosity:
What changes the distance a paper airplane travels?
At this point you do not need to know the answer. Curiosity gives you a reason to investigate.
Step 2: Ask a testable question
A useful scientific question should be specific enough that evidence can help answer it.
This question is very broad:
What makes a paper airplane good?
The word good could mean many things.
A more testable question is:
Does adding one paper clip to the nose of the same paper airplane design change how far it travels?
This question identifies something that can be changed and something that can be measured.
Clear questions make it easier to design useful investigations.
Step 3: Learn what is already known
Scientists do not normally begin every investigation from nothing.
They examine information that already exists.
For a school investigation, this might include:
- reading a reliable science source
- reviewing class notes
- checking how a measurement should be made
- learning whether someone has already investigated a similar question
Background research can help you improve the question and avoid repeating mistakes that are already understood.
It can also help you decide what evidence you need to collect.
Step 4: Develop a hypothesis
A hypothesis is a proposed explanation or answer that can be examined using evidence.
For the paper airplane question, a learner might write:
If one paper clip is added to the nose of the airplane, then the average flight distance will change compared with the same airplane design without the paper clip.
The important feature is not whether the hypothesis sounds clever.
It must be possible to test it.
A hypothesis is not something you need to protect
Sometimes learners think the purpose of an investigation is to prove that their hypothesis was correct.
That is not the goal.
The goal is to collect evidence and compare the evidence with the hypothesis.
The results may support the hypothesis, fail to support it or reveal that the original question needs improvement.
A hypothesis that is not supported can still lead to useful learning.
Step 5: Plan the investigation
Before collecting data, decide how the test will work.
A good plan should make it clear what you will do and what you will measure.
For the paper airplane example, you could compare:
- the airplane without a paper clip
- the same airplane design with one paper clip attached to the nose
You would also try to keep other important conditions as similar as reasonably possible.
For example, use the same paper airplane design, the same starting line, the same measuring method and the same testing area.
Repeating each condition several times can produce more useful evidence than relying on a single flight.
Write the procedure before you begin
A procedure is a clear description of what you plan to do.
A simple procedure might be:
- Prepare the paper airplane.
- Mark the starting line.
- Fly the airplane without the paper clip several times.
- Measure and record each flight distance.
- Add one paper clip to the nose.
- Repeat the flights using the same testing method.
- Measure and record each distance.
- Compare the results.
Writing the procedure first helps you notice unclear parts before the investigation starts.
Science investigations should be safe
Choose investigations that are appropriate for your age, location and available supervision.
Do not experiment with dangerous chemicals, electricity, fire, medicines, unknown substances, harmful microorganisms or activities that could injure people or animals.
School laboratory activities should follow the safety instructions provided by the teacher or responsible adult.
Step 5 continued: Carry out the investigation and record evidence
Follow the planned procedure as carefully as you can.
Record what happens rather than what you expected to happen.
Measurements might include:
- distance
- time
- mass
- temperature
- number of events
- another quantity connected to the question
Other investigations may also include descriptive observations.
Record information while the investigation is happening instead of relying on memory later.
Keep observations separate from expectations
Suppose you expected the airplane with the paper clip to travel farther.
One flight travels only three metres.
You should record three metres even if the result does not match your expectation.
Changing or ignoring inconvenient results would make the evidence less trustworthy.
Step 6: Analyze the data
After collecting the data, examine it carefully.
Do not jump directly from the first result to a conclusion.
You might:
- organize measurements in a table
- calculate an average when appropriate
- look for patterns
- compare different test conditions
- create a simple graph
- look for results that are very different from the others
For the airplane investigation, you could compare the typical flight distance without the paper clip with the typical distance when the paper clip is attached.
One surprising result deserves attention
Imagine most flights travel between four and six metres, but one flight travels twelve metres.
Do not automatically delete the unusual measurement.
First ask what might explain it.
Perhaps the throw was different. Perhaps there was a gust of wind. Perhaps the measurement was recorded incorrectly. Or perhaps the unusual result is real.
Good scientific thinking includes noticing unexpected evidence and deciding whether more testing is needed.
Step 7: Draw a conclusion
A conclusion explains what the collected evidence suggests about the original question.
A useful conclusion should connect directly to the data.
For example:
In these trials, the airplane with the paper clip had a shorter average flight distance than the airplane without the paper clip.
You could then state whether the results supported your original hypothesis.
Avoid making a much larger claim than your investigation can support.
A small classroom investigation does not automatically establish a universal rule about every paper airplane.
Do not say that one experiment proves everything
Scientific evidence can support an explanation, but conclusions remain open to further checking.
Other investigators may repeat the test, collect more observations, use different methods or discover evidence that changes the explanation.
This ability to test and revise ideas is an important strength of science.
Step 8: Communicate the results
Science becomes more useful when other people can understand what was done.
A simple investigation report may include:
- the question
- the hypothesis
- the procedure
- the observations and measurements
- the analysis
- the conclusion
- possible limitations
- questions for further investigation
Clear communication allows other people to examine your reasoning and possibly repeat the investigation.
Then the process can begin again
A conclusion often creates new questions.
After the airplane investigation, you might wonder:
- Would two paper clips produce a different result?
- Would another airplane design respond differently?
- Would changing the position of the paper clip matter?
- Would the pattern remain similar after many more trials?
Those questions can lead to another investigation.
This is why science is often better pictured as a cycle or network of connected activities rather than a straight line that ends forever after one conclusion.
Experiments are important, but science includes more than experiments
Some scientific questions can be investigated through controlled experiments.
Others depend heavily on observations, existing data, comparisons, field studies, models or evidence from events that scientists cannot recreate.
The methods vary, but scientists still ask questions, examine evidence, analyze information and construct explanations that can be evaluated by others.
What makes a scientific investigation useful?
A useful investigation should connect the question, method, evidence and conclusion.
Ask:
- Is the question clear?
- Can evidence help answer it?
- Does the method actually test the question?
- Were observations and measurements recorded carefully?
- Does the conclusion match the evidence?
- Are limitations acknowledged?
- Could someone understand what was done?
Common beginner mistakes
Starting with a question that cannot be tested
A question may be interesting but too broad or subjective for a simple investigation.
Make it more specific and identify evidence that could help answer it.
Treating the hypothesis as the correct answer
The hypothesis is something to examine, not something the data must agree with.
Changing several conditions without a clear plan
If many things change at once, it can become difficult to understand what produced the result.
Recording only results you expected
Record the evidence that actually appears.
Using one trial as the whole investigation
Repeated observations can help reveal whether a result is consistent.
Making a conclusion that is larger than the evidence
Explain what your investigation supports without claiming more than the data can show.
A quick scientific method check
Before finishing an investigation, ask:
- What did I observe or wonder about?
- What exactly was my question?
- What information did I check before testing?
- What was my hypothesis?
- How did I investigate it?
- What evidence did I record?
- What pattern did I find?
- What conclusion is supported by the evidence?
- What limitations should I mention?
- What question could I investigate next?
The main idea
The scientific method is best understood as organized evidence based inquiry rather than a rule that every scientist must follow in exactly the same order.
A beginner step by step model can help you learn the core habits: observe, ask a testable question, learn what is known, develop a hypothesis, investigate, collect and analyze evidence, draw a careful conclusion and communicate what you found.
Real scientific work can move backward and forward between these activities as new evidence and new questions appear.
Continue learning
The next Science Foundations article will explain the difference between an observation and an inference.
You will also use the ideas from this guide in a lesson where you turn a broad question into a testable hypothesis.