Dependent vs Independent Variable

Jhojan wants to find out if the kind of soil changes how tall a bean plant grows. He plants beans in sandy soil, clay soil, and potting soil. What is the independent variable?

• A.

  The kind of soil

• B.

  The kind of bean plant

• C.

  How tall the bean plant grows

• D.

  The amount of water

Answer explanation

This is the one thing the student changes on purpose to see what will happen.

In an experiment where Steven tests if the kind of soil changes how tall a bean plant grows, what is the dependent variable?

• A.

  Where the plants are

• B.

  The kind of soil

• C.

  The size of the pot

• D.

  How tall the bean plant is

Answer explanation

This is the result that is measured, and it depends on the kind of soil.

Brian wants to see if a special gaming mouse helps him get a higher score in a game. He tries playing with a regular mouse and then with the special mouse. What is the dependent variable?

• A.

  The computer game

• B.

  The kind of mouse

• C.

  The score in the game

• D.

  The time of day

Answer explanation

This is the result that is measured to see if the mouse made a difference.

Katerin and Charlie put different amounts of salt in water to see if that changes the water's boiling temperature. What is the independent variable?

• A.

  The amount of salt

• B.

  The amount of water

• C.

  The boiling temperature

• D.

  The kind of pot used

Answer explanation

This is the one thing the scientist changes on purpose in each test.

Juan and Luella want to know if the color of a car changes how hot it gets in the sun. In this experiment, the color of the car is the dependent variable.

• True

• False

Answer explanation

The color is what is changed on purpose (independent variable). The temperature is what is measured (dependent variable).

Alex and Sofia are conducting an experiment to see how the amount of sunlight affects the growth of a plant. The thing they measure in the experiment to see the results is called the independent variable.

• True

• False

Answer explanation

The thing you measure is the dependent variable. The independent variable is what you change.

Maria wants to see if a puppy gains more weight by eating Brand A food or Brand B food. In this experiment, the puppy's weight is the dependent variable.

• True

• False

Answer explanation

The puppy's weight is the result that is measured, and it depends on the kind of food.

Steven and Sofia are conducting an experiment. The independent variable is the one thing they change on purpose in their experiment.

• True

• False

Answer explanation

This is the correct definition for an independent variable.

Brian and Lina are testing which fertilizer helps a plant grow tallest. In their experiment, the height of the plant is the independent variable.

• True

• False

Answer explanation

The height of the plant is the result you measure (dependent variable). The kind of fertilizer is what you change (independent variable).

Lina and Karla want to test how the amount of sunlight changes a flower's color. The amount of sunlight is the independent variable.

• True

• False

Answer explanation

The amount of sunlight is the one thing you are changing on purpose to see what effect it has.