Independent variables Examples

Independent variables are essential to scientific work and the scientific method. An independent variable in an experimental setup is the manipulated variable. In other words, the independent variable is the variable that is being tested or altered by the experimenter. It is vital to the accountability of the experiment that only one independent variable is tested so that one can see the effects of changing that single variable. If more than one independent variable is used, then the experimental results are compromised.

1. In an experiment to test how the amount of sunlight affects the growth of radishes. The independent variable is the amount of sunlight each plant receives.

2. In an experiment to test the effect a gasoline additive has on gas mileage in a car, the amount of additive per gallon is the independent variable.

3. In an experiment to test the effect of eating carbohydrates on weight loss, the amount of carbohydrates eaten daily is the independent variable.

4. In an experiment to test the effect of sleep deprivation on student test scores, the amount of sleep a student would get nightly is the independent variable.

5. In an experiment to test the effect an insecticide has on keeping earwigs out of the house, the independent variable is the type of insecticide used.