Parts of an ExperimentParts of an Experiment

VariablesVariables

All of the factors thatcould be changed inan experimentConstantsIndependentDependent

Independent VariableIndependent Variable

The variable “you” choose to change or test.

Examples include: amount of water, sunlight or drop height.

The variable “you” choose to change or test.

Examples include: amount of water, sunlight or drop height.

Dependent VariableDependent Variable

The variable you are observing or measuring

This variable depends on the independent

Example: The height of the plant depends on other variables such as the amount of water or sunlight

The variable you are observing or measuring

This variable depends on the independent

Example: The height of the plant depends on other variables such as the amount of water or sunlight

Constants (Controls)Constants (Controls)

The variables that STAY THE SAME to help you compare your results

The variables that STAY THE SAME to help you compare your results

ExampleExample

You want to see different colored light bulbs affect the growth of bean plants.

• Write a hypothesisI predict plants grow taller in white

light

You want to see different colored light bulbs affect the growth of bean plants.

• Write a hypothesisI predict plants grow taller in white

light

What is the independent variable?

What is the independent variable?

Color of lightColor of light

What is the dependent variable?

What is the dependent variable?

Plant growthPlant growth

What variable should be held consant?

What variable should be held consant?

Water, soil, type of plant

Water, soil, type of plant