Identify the variable that is changed or controlled
The changed or controlled variable is the independent variable
Identify the variable that is measured or observed
The measured or observed variable is the dependent variable
Ask which variable causes the change
Ask which variable responds to the change
In an experiment, the independent variable is the input
In an experiment, the dependent variable is the output
If one variable is manipulated and the other is recorded, the manipulated one is independent
If one variable depends on the other, the dependent one is dependent