Simple Experiment Fair
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What you will learn
- 1Design a simple science experiment with question, prediction, method, result, and conclusion
- 2Change only one variable in an experiment to make results reliable
- 3Present experiment findings clearly using evidence
Mini Lesson
Real scientists share their discoveries with other scientists. In this project, you will choose a question from anything you learned this year, design a simple experiment to test it, carry it out with a grown-up, and present your results — just like a real science fair!
The five parts of an experiment
- Question: A clear scientific question you can test — for example, "Does a plant grow taller in sunlight or shade?"
- Prediction (hypothesis): What you think will happen — "I think ___ because ___."
- Method: The materials and steps to test your prediction. Change only ONE variable.
- Result: What you observed — numbers, sketches, and notes.
- Conclusion: Was your prediction correct? What does the evidence show?
Keeping your experiment fair
- Change only one variable at a time — if you change two things, you cannot tell which one caused the result.
- Keep everything else the same: same pot, same soil, same water, same time of day.
- Record observations carefully with numbers, measurements, and drawings.
- Repeat the experiment if you can — more trials make the result more reliable.
Sharing your work
- Make a poster or folded display board with all five parts clearly labeled.
- Practice presenting aloud: state your question, prediction, result, and conclusion.
- Answer questions from your audience honestly — even "I don’t know yet" is a good answer.
Words to know
Hypothesis
A testable prediction about what will happen in an experiment
e.g. "I think the plant in sunlight will grow taller."
Variable
The one thing you change in an experiment to test your question
e.g. the amount of sunlight a plant receives
Observation
Information gathered by watching, measuring, or sensing during an experiment
e.g. "The shaded plant is 3 cm shorter after one week."
Evidence
Accurate, checkable data that supports or contradicts a hypothesis
e.g. a table of plant heights measured each day
Conclusion
A summary of what the evidence shows and whether the hypothesis was supported
e.g. "Sunlight helped my plant grow taller — my prediction was correct."
Experiment
A careful test that follows a method to answer a scientific question
e.g. growing two plants under different conditions to compare them
Write your five parts like a recipe: each step clear enough that a friend could repeat your experiment exactly the same way.
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