Fair Testing

What is a fair test?

• It is any experiment.

• It is an experiment with one changed variable.

• It is an experiment with many changed variables.

• It is an experiment without any changed variable.

How many variables are changed in these 2 set-ups?

• 1

• 2

• 3

• 4

Which is the changed variable in this fair test?

• type of soil

• amount of soil

• number of seedlings

• size of pot

Daniel wants to find out if seeds need warmth to germinate. Look at his set-ups after a few days.

What is the changed variable here?

• temperature

• amount of light

• number of seeds

• presence of water

Miss Lim wants to find out if seeds need light to germinate. Which set-ups should she use?

• A : 3 seeds , wet cotton wool, placed in a cup near the window

  B: 2 seeds , wet cotton wool, placed in a cup near the window

• A: 3 seeds , wet cotton wool, placed in a cup near the window

  B: 3 seeds , wet cotton wool, placed in a cup in a dark cupboard

• A : 3 seeds , wet cotton wool, placed in a cup near the window

  B: 3 seeds , wet cotton wool, placed in a cup in the fridge

• A : 3 seeds , wet cotton wool, placed in a cup near the window

  B: 3 seeds , dry cotton wool, placed in a cup near the window