Experimental Design (IVCDV)

The type of variable that you change or manipulate in an experiment.  It is what you are testing.

• Independent
• Dependent
• Control

The type of variable that responds to the experiment and is what you measure to determine if your hypothesis is true.

• Independent
• Dependent
• Control

The parts of the experiment that must be kept the same.

• Constants
• independent
• Dependent

If I water the plant more often, then it will grow taller.  Name the independent variable.

• The height of the plant
• The size of the pot
• The amount of water
• The amount of light.

If I water the plant more often, then it will grow taller.  Name the dependent variable.

• The amount of water.
• The amount of soil.
• The height of the plant.
• The amount of water.

Which of these is not an observation.

• There are footprints.
• The person was dizzy.
• The footprints are black.
• There are dots.

When you make a prediction based upon your observations, it is called a/an _____________.

• Inference
• Observation
• Control group
• Guess

Which of these would be the proper way to write a hypothesis

• I think the water will make the plant grow.

• Watering plants will make them grow better.

• If I add more water, then the plant will grow taller.

• Maybe water will make a plant grow taller.

Students used various temperatures of water to see which one dissolved candy faster. 
What was the Independent Variable?

• Amount of Candy
• Amount of Water
• Temperature of Water
• Time for Candy to Dissolve

Students wanted to see if the type of material affected the temperature after being placed under a heat lamp for 10 minutes.

What is the dependent variable for this investigation?

• Type of material (rocks, sand etc)

• Temperature after 10 minutes

• Time under the lamp

• Heat lamp, amount of material