Scientific Method & Fair Tests
- 1Print it first. Read it once together and talk it through.
- 2Exercises on paper, then correct together with the answer key.
- 3Next day: a 10-minute review here on screen saves progress.
What you will learn
- 1Name the steps of the scientific method in order
- 2Explain what makes an experiment a fair test
- 3Identify independent, dependent, and controlled variables
- 4Use evidence to draw a clear conclusion
Mini Lesson
Scientists use the scientific method to answer questions about the world. It is a step-by-step process that turns curiosity into evidence. Each step builds on the one before it, and a good scientist can repeat the process to refine an idea.
The Five Steps
- Question — ask a clear, testable question about something you observe.
- Hypothesis — predict what you think will happen and why.
- Experiment — test the hypothesis with a fair, careful procedure.
- Data — record measurements and observations as you go.
- Conclusion — explain what the data shows, using evidence.
What Makes a Fair Test
A fair test changes only one thing at a time. That way, you know which change caused the result. Scientists call the things they change, measure, and keep the same the variables of the experiment.
- Independent variable — the one thing you change on purpose.
- Dependent variable — what you measure to see the effect.
- Controlled variables — everything else you keep the same.
Example: Do Plants Grow Taller in Sunlight?
- Independent: amount of sunlight (full sun vs. shade).
- Dependent: plant height after two weeks.
- Controlled: same plant species, same soil, same water, same pot size.
- Conclusion is only fair if every other condition stayed the same.
Words to know
hypothesis
A prediction about what will happen, based on what you already know.
fair test
An experiment that changes only one variable at a time.
independent variable
The one thing the scientist changes on purpose.
dependent variable
What the scientist measures to see the effect.
controlled variable
Everything else that is kept the same so the test is fair.
Tip: if more than one thing changes between trials, you cannot tell which change caused the result. Change one variable, keep the rest the same.
Guided Practice
Exercises
Sort each example into the correct step of the scientific method.
1. Question
2. Hypothesis
3. Experiment
4. Data
5. Conclusion
Put the steps of the scientific method in the correct order.
Pick the best answer for each question.
1. Which step of the scientific method comes FIRST?
2. A hypothesis is best described as...
3. You change the amount of sunlight a plant gets to see how it grows. Sunlight is the...
4. In the same plant experiment, the plant's height after 2 weeks is the...
5. Which of these would NOT be a fair test?
6. After running an experiment, what should you do with your data?
7. A controlled variable is...
8. Which question is the MOST testable in a science experiment?
Parent Checklist
For the parent: after correcting together, check off what your child has really understood