Experimental Design--ID IV, DV, Constants and Controls
For each experimental question, identify the independent variable (IV), dependent variable (DV), constants and the control.
For Each, Ask Yourself:
What am I changing on purpose so that I can answer my question? -- this is your Independent Variable.
What is being measured? What data (numbers) are being collected? --this is your Dependent Variable.
What is staying the same in all of the exeriments? -- these are your Constants.
What is your zero IV level? What is your normal group that does not recieve any testing.---This is your Control
Does the brand of allergy medication affect the number of times a person sneezes?
No allergy medicine
The brand of medicine
The person taking the medicine
The amount of allery medicine
The number of sneezes
The time of day medicine is taken
Independant Variable
Dependent Variable
Constants (3)
Control
Does the amount of soil a plant is placed in affect how tall it grows?
No soil
amount of water
Height of plant (in cm)
Amount of soil
type of plant
amount of sunlight
Independant Variable
Dependent Variable
Constants (3)
Control
Which type of sunscreen prevents burns for the longest amount of time?
Time to burn (minutes)
skin tone of persons being tested
Time of day
amount of sunscreen used
Brand of sunscreen
No sunscreen
Independant Variable
Dependent Variable
Constants (3)
Control
What paper towel brand absorbs the most water?
Size of paper towel
Amount of water absorbed (mL)
None (need a paper towel to absorb any water)
Temperature of water
Brand of paper towel.
Surface water is spilled on
Independant Variable
Dependent Variable
Constants (3)
Control
Sam wants to figure out which pan cooks eggs the fastest: bronze, copper or steel.
Size of eggs
Minutes until egg is cooked
Temperature stove burner is set on.
Size of pans
None (can't cook eggs without a pan)
Material pan is made out of.
Independant Variable
Dependent Variable
Constants (3)
Control
Ashton wants to see which fast food restaurant has french fries that will take the longest to grow mold.
French fries are on the same table
Time to grow mold (days)
Handle french fries with gloved hands
None (can't test without french fries)
Number of french fries
Fries from different restraurants
Independant Variable
Dependent Variable
Constants (3)
Control
Which brand of dish soap makes the most amount of suds?
Volume of suds (mL)
Time water and soap is stirred
None (need suds to make bubbles)
Amount of dish soap
Amount of water
Brand of dish soap.
Independant Variable
Dependent Variable
Constants (3)
Control
What type of physical activity gives you the highest heart rate?
Time spent on activity
Type of physical activity
Person doing the activity
Heart rate (beats per minute)
Outside temperature
Sitting (no activity)
Independant Variable
Dependent Variable
Constants (3)
Control
What type of detergent gets out grass stains the best?
Size of original stain
Same wash cycle
Area of stain removed (cm^2)
Brand of detergent
washed in water without detergent
Type of original stain
Independant Variable
Dependent Variable
Constants (3)
Control