Understanding Fair Tests and Variables

Why is it important to conduct a fair test in an experiment?

• To get random results

• To ensure accuracy and reliability

• To change multiple things at once

• To make the experiment more difficult

Which of the following is an example of an investigable question?

• What is the best plant in the world?

• What happens to plant growth if we add fertiliser?

• Why do plants need sunlight?

• Can plants feel emotions?

What should a good scientific question always include?

• A random guess

• Something that cannot be tested

• A testable and measurable factor

• A yes or no answer

What is the independent variable in an experiment testing fertiliser on plant growth?

• The height of the plant

• The amount of fertiliser added

• The amount of sunlight

• The type of soil used

Which variable is the dependent variable in the fertiliser experiment?

• The type of plant used

• The amount of water given

• The plant’s growth (height)

• The size of the pot

Why do we need a control in an experiment?

• To make the experiment harder

• To compare changes against something unchanged

• To make sure all plants grow the same

• To speed up the experiment

Which of the following is an example of a controlled variable in a plant growth experiment?

• The amount of fertiliser added

• The type of plant used

• The plant’s height over time

• The number of leaves growing

What happens if you change more than one variable at a time in an experiment?

• The results will be more accurate

• You won’t know what caused the change

• The experiment will be faster

• The experiment will be fairer

In a fair test, which variable do you observe and measure?

• Independent variable

• Dependent variable

• Controlled variable

• Random variable

If you were testing the effect of sunlight on plant growth, what would be a controlled variable?

• The height of the plant

• The number of hours of sunlight

• The amount of water given to each plant

• The type of soil used