Experimental Design

The one factor that a scientist changes during an experiment.

• Controlled Variable

• Dependent Variable

• Independent Variable

The variable that is measured.

• Controlled Variable

• Dependent Variable

• Independent Variable

Why is it important to have only one independent variable and to control the other variables when performing science experiments?

• So you can tell which factor is causing the change in the experiment.

• It does not matter, you can have as many independent variables as you want.

Ben makes five paper helicopters with different wing lengths. He drops them the same way from a height of two meters for five trials each. He records the amount of time it takes for each helicopter to fall to the ground.

What is the independent variable?

• Dropping the same way

• Wing Length

• Amount of time it takes the helicopter to hit the floor

• Dropping from the same height

Ben makes five paper helicopters with different wing lengths. He drops them the same way from a height of two meters for five trials each. He records the amount of time it takes for each helicopter to fall to the ground.

What is the dependent variable?

• Dropping the same way

• Wing Length

• Amount of time it takes the helicopter to hit the floor

• Dropping from the same height

Ben makes five paper helicopters with different wing lengths. He drops them the same way from a height of two meters for five trials each. He records the amount of time it takes for each helicopter to fall to the ground.

What are two controlled variables? (Select 2 answers)

• Dropping the same way

• Wing Length

• Amount of time it takes the helicopter to hit the floor

• Dropping from the same height

Mrs. Ahlers set up an experiment to see how the mass of a ball affects the distance it rolls off a ramp. What is the dependent variable?

• Distance traveled by the ball
• Height of the ramp
• Mass of the ball
• Where the experiment took place.

What is a hypothesis?

• the thing changed on purpose in the experiment

• an explanation about what you observed

• using your 5 senses to gather data

• an educated guess about the outcome of an experiment

What two words should be in your hypothesis?

• I think

• If ...then...

• It will

• No idea

Tags

NGSS.HS-LS4-4

NGSS.HS-PS1-2

When is a hypothesis written?

• before you decide on a question

• after the experiment

• before the experiment

• after the conclusion