How can you turn an interesting observation into a science question you could actually investigate?
A broad question can start your thinking, but an investigable question is focused enough to guide observations or measurements. It names what you will change or compare and what result you will measure. That result is the outcome variable.
For example, “Why does ice melt?” is too broad for one short investigation. A focused question could compare two surfaces and measure melting time. The question should not assume the answer. You are planning evidence, not claiming a cause before collecting data.
I can write a focused science question and evidence plan so I can design an investigation that could answer it.
- My question names one comparison and one measurable outcome.
- My evidence plan explains what I would measure and repeat.
- I do not assume a cause before I have evidence.
Your core challenge
Observation: A paper helicopter with longer blades appears to stay in the air longer than one with shorter blades.
Write 3–5 sentences that answer two questions:
1. What focused science question could test this observation?
2. What evidence would you collect to answer it?
Sentence starter: “How does ___ affect ___? I would compare ___ and measure ___.”
Optional stretch challenge
Name two conditions you would keep the same, such as paper type, drop height, or helicopter body size, to make the comparison fair.
A quick question ladder
Describe what you observe.
Name one factor to change.
Name the outcome to record.
Plan several trials.
Worked example: a different problem
Observation: Equal-size ice cubes seem to melt at different speeds on metal and plastic trays.
Focused question: How does tray material—metal or plastic—affect the time an equal-size ice cube takes to melt under the same room conditions?
Evidence plan: Place equal-size cubes on each tray at the same time, record total melting time, and repeat the comparison several times. Keep the starting cube size and room conditions as similar as possible.
The example asks about a relationship; it does not claim in advance that the tray caused the difference. A conclusion would need to match the evidence collected.
Check and revise
- Can a reader identify exactly what you will compare?
- Is the outcome observable or measurable?
- Did you explain what data you would collect and repeat?
- Did you avoid words such as proves, always, or an assumed cause?
Compare with one possible answer
How does paper-helicopter blade length affect the time the helicopter takes to fall two meters? I would make helicopters from the same paper and change only the blade length. I would release each one from the same height, measure its fall time, and repeat each version several times.
If your question uses the word better, revise it by naming a measurable outcome such as fall time.
Record your response in your notebook or your teacher’s assigned response space. For more investigations, explore the virtual labs.
Source and teacher note
The Next Generation Science Standards practice page on asking questions and defining problems describes how middle-school questions specify relationships among variables and clarify evidence. The classroom scenarios here are original teaching examples.
