What are the 3 main variables within a scientific experiment?

• The independent variable is what you change throughout the experiment. Some examples of this may be temperature, pH, light levels or time. • The dependent variable is what is being measured. This is expected to change in response to the changing independent variable. • The control variable is kept constant throughout the experiment to ensure it does not have an effect on the dependent variable. If this variable changed it would invalidate the results, as it would not be known if the results were due to the change in the independent variable or a change in another variable.