Experimental Design and Variables Review

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

"Does eating breakfast improve test scores?"

• eating breakfast or not

• the grade you got on the test

• what time you get up in the morning

• how tasty the breakfast is

You are testing how the amount you water a plant affects its growth. What would be the INDEPENDENT VARIABLE in this experiment.

• They type of pot you put the plants in.

• The amount you water each plant.

• The amount of sunlight the plants get.

• The amount the plant grows.

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

An experiment is performed 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, the independent variable is ...

• The type of plant
• The amount of sunlight
• The type of music
• The type of liquid

Mr. Pransky wants to see how different surfaces affect how high a tennis ball can bounce. What is the independent variable?

• the different surfaces

• using the same ball

• how high they bounce

A student wants to test the hypothesis of "If salt is added to water then the boiling point of water will decrease (go down)." What is the independent variable?

• Whether salt is added or not

• Boiling Point

• Amount of water

If you were testing the time it took for objects of different sizes to reach the ground after being dropped from 30 feet in the air, which of these would be the DEPENDENT VARIABLE?

• The time it takes for each object to hit the ground.

• The size of each object.

• The type of object you use.

• The height you drop the object from

Sadie is testing how the age of a seed affects how fast plants grow. Look at the picture to see if you can figure out what makes her experiment unfair. Mark all that apply.

• She used different types of seeds/plants.

• The plants are in different pots.

• She did not plant very many plants.

• Seed age might not make a difference.

Tags

NGSS.MS-LS1-5

Steve wanted to see if the type of fertilizer made sunflowers grow larger. What is the independent variable? 

• Type of fertilizer
• Size of sunflower
• type of sun flower

Tags

NGSS.MS-LS1-5

Molly investigated if the age of students caused them to be better drivers. What is the dependent variable?

• Type of car
• Skill of driving
• Age of student

Mrs. Cote wanted to know if the iPhone could stand up against being dropped from different heights. She dropped them from 3 heights and saw if they broke. What is the dependent variable?

• Drop height
• If they had a case on them or not
• If they broke