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What Is a Fair Test?

Lesson Plan

What Is a Fair Test?

Students will be able to define a fair test and identify variables that need to be kept the same in a scientific investigation to ensure a fair test.

Understanding fair tests is essential for conducting reliable scientific experiments and drawing accurate conclusions. This skill helps students develop critical thinking and problem-solving abilities applicable to many areas of life.

Audience

4th Grade

Time

30 minutes

Approach

Through guided discussion, examples, and an interactive activity, students will grasp the concept.

Materials

Whiteboard or projector, Fair Test Slides, Fair Test Warm-Up, Fair Test Activity: Paper Airplanes, and Fair Test Cool-Down

Prep

Teacher Preparation

10 minutes

Step 1

Warm-Up: Think About It!

5 minutes

  1. Distribute the Fair Test Warm-Up or display the prompt on the board.
    2. Ask students to silently think about the question: "Imagine you want to find out which type of ball bounces the highest. How would you test it fairly?"
    3. After 2 minutes, have students share their initial thoughts with a partner.
    4. Briefly bring the class together and ask a few pairs to share one idea they discussed. (e.g., "use the same height," "drop them on the same floor")

Step 2

Introduction to Fair Test

10 minutes

  1. Use the Fair Test Slides to introduce the concept of a fair test.
    2. Start with Slide 2: "What is a Fair Test?" Explain that a fair test means changing only one thing at a time to see its effect.
    3. Move to Slide 3: "Why are Fair Tests Important?" Discuss how fair tests help us trust our results.
    4. Use Slide 4: "Variables!" to explain what variables are (things that can change). Give examples.
    5. Use Slide 5: "The 'Only One Changer' Rule." Emphasize keeping everything else the same.
    6. Discuss the warm-up question again in light of the new definitions. What are the variables? What should stay the same? What should change?

Step 3

Activity: Paper Airplanes

10 minutes

  1. Introduce the Fair Test Activity: Paper Airplanes.
    2. Explain that students will design and test paper airplanes, but with a focus on fair testing.
    3. Display Slide 6: "Paper Airplane Challenge."
    4. Explain the challenge: "Which design makes a paper airplane fly the furthest?"
    5. Guide students to identify variables (e.g., type of paper, throwing force, design, starting height).
    6. Instruct students to keep all variables the same EXCEPT for ONE aspect of the airplane design (e.g., wing shape, nose type).
    7. Have students work individually or in pairs to fold two different airplane designs, ensuring they only change one variable between the two.
    8. Briefly test their airplanes in a designated area, emphasizing fair testing practices (e.g., throwing from the same spot, with similar force).

Step 4

Cool-Down: Reflect and Connect

5 minutes

  1. Distribute the Fair Test Cool-Down or display the prompt on the board.
    2. Ask students to reflect on the paper airplane activity and answer the question: "Why was it important to make sure your paper airplane test was fair? Give an example of something you kept the same."
    3. Collect the cool-down responses as an exit ticket.
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Slide Deck

What Makes an Experiment FAIR?

Today, we're learning how to make sure our science experiments give us honest answers!

Greet students and prepare to introduce the concept of a fair test. Connect to the warm-up activity.

What Is a Fair Test?

In a fair test, you only change ONE thing to see how it affects your results.

Everything else stays the SAME!

Explain that a fair test is about changing only one thing to see what happens. Use simple language and an everyday example if needed (e.g., trying a new recipe ingredient).

Why are Fair Tests Important?

Imagine you're trying to figure out if sunlight helps a plant grow.

What if you also gave one plant more water AND different soil?

You wouldn't know if it was the sunlight, water, or soil that made the difference!

Discuss why fair tests are important. If you change too many things, you won't know what caused the result.

Variables! (Things That Can Change)

A variable is anything that can change or be changed in an experiment.

Think about:

  • The type of ball you use
  • The height you drop it from
  • The surface it bounces on

Introduce the term 'variables' as things that can change. Give a few simple examples relevant to 4th graders (e.g., shoe color, height, favorite food).

The 'Only One Changer' Rule

To have a fair test, you must:

  1. Change ONLY ONE thing (This is what you are testing!)
  2. Keep EVERYTHING else the SAME (These are your 'controlled' variables)

Example: Testing which ball bounces highest

  • Change: Type of ball (soccer ball vs. basketball)
  • Keep the same: Drop height, surface, how you drop it

Reinforce the key rule: only one variable should be changed (the independent variable), while all others (controlled variables) are kept constant. Use the example of the ball bounce.

Paper Airplane Challenge!

Today, you'll be junior engineers!

Challenge: Which paper airplane design flies the furthest?

Think: What will you change? What will you keep the same?

Introduce the paper airplane activity. Guide students to think about what they will change and what they will keep the same.

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Warm Up

Fair Test Warm-Up

Think About It!

Imagine you want to find out which type of ball bounces the highest. You have a basketball, a tennis ball, and a golf ball.

How would you test them fairly to see which one bounces highest?







Share with a Partner:

Tell your partner one idea you had about how to make the test fair.




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Activity

Fair Test Activity: Paper Airplanes

The Challenge: Which paper airplane design flies the furthest?

Your Goal:

Design two different paper airplanes to test which design flies furthest. You need to make sure your test is FAIR!

How to Make it Fair:

  1. Choose ONE thing to CHANGE between your two airplane designs (e.g., wing shape, nose fold, size).

    • Example: Airplane 1 has wide wings, Airplane 2 has narrow wings. (Only the wing shape changes!)

  2. Keep EVERYTHING else the SAME when you test your airplanes.

    • Same starting point: Throw from the exact same spot.
    • Same throwing force: Try to throw both airplanes with similar strength.
    • Same type of paper: Use the same kind of paper for both airplanes.
    • Same thrower: You should throw both airplanes.

Your Plan:

Airplane 1 Design Idea:


Airplane 2 Design Idea (changing only ONE thing from Airplane 1):



Testing Your Airplanes:

  1. Find a clear space to launch your airplanes.
  2. Mark your starting line.
  3. Launch Airplane 1. Mark where it lands.
  4. Launch Airplane 2 from the exact same starting line and with similar force. Mark where it lands.
  5. Measure the distance each airplane flew.

Reflection:

What was the one thing you changed between your two airplane designs?


What are some things you kept the same to make sure your test was fair?


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Cool Down

Fair Test Cool-Down

Reflect and Connect

  1. During our paper airplane activity, why was it important to make sure your test was fair?




  2. Give one specific example of something you kept the same to make your paper airplane test fair.




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What Is a Fair Test? • Lenny Learning