Variables

Independent variable - The factor (thing) that is intentionally changed; it causes a change. There should never be more than one independent variable.

Dependent variable - The factor (thing) that changes as a result of the independent variable. It is the factor that is measured during the experiment.

Controlled variable - The factors (things) that are not changed in the experiment. They are kept intentionally the same.

Control group - A group of subjects that is not exposed to the independent variable.