Identifying the Variable

The independent variable is the ONE thing you _____.

• change
• keep the same
• experiment with
• investigate

The variable that you measure is the -

• IV
• DV
• Constant
• Repeated Trial

How many variables can be tested in a controlled experiment?

• one
• two
• three
• as many as possible

Dr. Eversole sets up an experiment on plants to see how different liquids affect plant growth. Each plant in the experiment is given a different liquid; water, apple juice, or milk. Each plant has the same amount of soil, sunlight, and listens to the same music. In this investigation, what is the independent variable?

• Type of plant

• Water, apple juice, milk

• Plant growth

Mr. G normally uses praise as a reward to train his dog. He wants to know the best way to train his dog, so he sets up an experiment to find out if there is a better way to get his dog to respond to commands. What is his dependent variable?

• Type of reward

• Praise

• Type of dog

• Amount of time the dog follows commands

Mrs. Register sets up an experiment to see how the mass of a ball affects the distance it rolls off a ramp. Identify the constant.

• distance traveled by the ball

• height of the ramp

• mass of the ball

• weight of the ball

What is the dependent variable (effect) is this experiment?

"Does eating breakfast improve test score?"

• eating breakfast or not

• the grade you got on the test

• what time you get up in the morning

• how tasty the breakfast is

What is the independent variable (cause) is this experiment?

"Which type of medium (soil or sand) is best for plant growth?"

• height of plant (cm)

• type of medium (soil or sand)

• amount of medium (soil or sand)

• types of plant

What is the dependent variable (effect) in this experiment?

"Do tall people jump further than short people?"

• height of the person

• weight of the person

• how fast the person runs

• how far the person jumps

What is the independent variable (cause) in this experiment?

"Which type of metal, copper or aluminum, conducts heat faster?"

• size of metal

• types of metal

• time it takes to heat up

• shape of the metal