Independent vs Dependent Variables in Science

Marbella, Ziqi, and Caylie are conducting experiments for their school science fair. Can you help them identify the independent and dependent variables and explain their relationship in each of their experiments?

• Marbella's experiment: The independent variable is the amount of water she gives to her plants, the dependent variable is the growth of her plants.

• Ziqi's experiment: The independent variable is the number of hours he practices piano, the dependent variable is his performance score.

• Caylie's experiment: The independent variable is the amount of sunlight his solar panel receives, the dependent variable is the amount of electricity it generates.

• Group experiment: The independent variable is the type of music they play, the dependent variable is the concentration level of the students studying.

Marbella, a young scientist, is curious about how different amounts of sunlight affect the growth of her garden plants. She sets up three groups of plants: one group in full sunlight (taken care by JayDyn), one in partial sunlight (monitored by DJ), and one in shade (looked after by Cody and Courtney). Identify the independent variable in Marbella's experiment.

• Water temperature given to the plants

• Number of plants in each group

• Amount of sunlight

• Type of soil

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

Ziqi is conducting a study on the effect of temperature on the rate of chemical reactions. She is using different temperatures to see how it affects the speed of a specific reaction. In this scenario, what is the dependent variable?

• Rate of chemical reactions

• Color of the chemicals Ziqi is using

• Volume of the chemicals Ziqi is using

• Temperature Ziqi is setting

Tags

NGSS.MS-PS1-4

Picture this, DJ and Cody are having a friendly discussion. DJ believes that drinking water before a meal influences the amount of food a person consumes. Cody, however, isn't so convinced. Ziqi, being the researcher she is, decides to conduct an experiment to resolve the discussion. In this scenario, what would be the dependent variable?

• Amount of food a person eats

• Time of day the meal is eaten

• Color of the drinking water

• Type of food being eaten

In an experiment, the factor that is changed is called the...

• independent variable

• dependent variable

• control

• spam

In an experiment, an independent variable is...

• Something that remains the same.

• Something that is changed.

• A constant

• The hypothesis

Tags

NGSS.MS-PS2-2

Squidward found new reeds to tryout for his clarinet.  He used an APPLAUSOMETER to measure applause after playing  Under the Sea with each reed.  The results were put in the table.
What was the independent variable?

• The Song

• The Reed size

• The Applause

In any experiment, the independent variable ______________.

• remains the same to not mess up the experiment

• is purposely changed to test the hypothesis

• is known by the scientist before doing the experiment

Tags

NGSS.MS-PS2-2

Steve wanted to see if the type of fertilizer he uses in his garden makes his sunflowers grow larger. If he did an experiment to find this out, what would be the independent variable?

• Type of fertilizer

• Size of sunflower

• type of sun flower

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

Why is it important to only change the independent variable in an experiment?

• It's not important.

• To keep the experiment fair.

• To prove your hypothesis correct

• To make sure you have enough detail for your conclusion.

Tags

NGSS.MS-PS2-2