Lesson 2 of 9 · Data and Evidence

Experiment⭐ 30 XP

Fair Tests and Controlled Variables

🧪Lab Brief #2

Data and Evidence.

🎯 Your mission

Run the experiment. Find out what really happens.

⚡ The twist

Nature loves to surprise the careful watcher.

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Mind = Blown

🔬 The more you look, the more nature shows you.

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Make a hypothesis first

Before you start: write down what you think will happen, and why.

What You'll Learn

A fair test changes one thing at a time and holds everything else steady. If you change the ramp angle and the ball at once, a difference in distance tells you nothing about which change caused it.

Key Words

Tap a word to see its definition.

Materials Needed

ramp
ball
metre rule
notebook

Safety First

Clear the run-out area so nobody trips on a rolling ball.

Steps

Step 1 — Read

Read the explanation above and note the two key terms before you start.

Step 2 — Do

Roll the same ball down a ramp at three angles, keeping release point, surface and ball identical. Record distance travelled three times per angle, then deliberately change two things at once and show why that run is uninterpretable.

Step 3 — Observe

Record what actually happened, including anything that did not match what you expected.

Step 4 — Record

Write a conclusion that answers the question this lesson opened with, and state your uncertainty.

Check Your Understanding

Question 1

1 of 2

In a fair test you change:

How sure are you going to be?😐 maybe

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Where you see this in real life

This shows up in your everyday life more than you'd think.

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Stretch Challenge

Try this in real life this week.

Try one experiment in real life this week — even a tiny one.

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For the dinner table

“What's the most surprising thing you learned today?”

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Next Smart Experiment

We'll pick an experiment that matches exactly how you're thinking right now.

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Send it to a parent who's looking for a 10-minute kitchen science win.

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