⚖️ Phase 2 - Encounter 🎞️ Slides ⏱ 4 minutes

Task 2 - How Do You Make a Test Fair?

First contact with the method: a comparison only means something when every product is tested the same way.

Step 1 - Watch a little water, then a lot

💧

🧻

A little water

💧💧💧

🧻

A lot of water

Step 2 - Have I proved anything?

"Product A absorbed more water. Have I proved that it is better?"

Not yet - the amounts poured on each sheet were different. That's not a fair test. Let's learn the rules.

Step 3 - The four Fair Test Rules

Rule 1 / 4

🧻 Same Product Category

Compare like with like. A product category is the type of product you're testing - here, kitchen towels, not towels against napkins.

🔁 Same Method

Every product completes exactly the same test - same amount of water, same time, same way of measuring. A method is the exact step-by-step procedure you repeat for every product.

📏 Measure, Don't Guess

Use numbers where possible. An observation ("it feels thicker") is not the same as a measurement ("it absorbed 35 ml").

🔂 Repeat

One result may be an accident. Professional consumer organisations (for example ZPS) decide their test methods before testing and use the same criteria for every product.

Step 4 - Two quick thinking questions

Can my test be as accurate as a professional laboratory?

Can I make my test systematic, transparent and repeatable?

Now let's see if you can spot fair and unfair tests yourself.

← Task 1 Continue to Task 3 →

What happens in Task 2

A 4-minute Phase 2 - Encounter activity. Students watch a split-screen pouring clip, vote on whether more absorbed water proves a product is better, go through four Fair Test Rule slides with tappable key terms, then answer two thinking questions.

🎯 Learning objectives

To understand that a comparison only means something when every product is tested in the same way, and to meet the four Fair Test Rules before running any real test.

♿ SEN Adaptations