Independent variables are the variables that the experimenter changes to test their dependent variable.

For example, a scientist is testing the effect of light and dark on the behavior of moths by turning a light on and off. The independent variable is the amount of light and the moth's reaction is the dependent variable.

A change in the independent variable directly causes a change in the dependent variable.

If the dependent and independent variables are plotted on a graph, the x-axis would be the independent variable and the y-axis would be the dependent variable.

### More About Variables

What Is a Variable in Science?What Is a Dependent Variable?

What Is a Control Group?

What Is an Experimental Group?