The independent variable is the one variable that an individual must change during an experiment in order to investigate or test the dependent variable. Basically their relationship to the experiment or between themselves can be easily remembered through their names: The independent variable is the one that's controlled by the researcher and therefore does not <em>depend</em> on other variables from the experiment (amount of UV light), the dependent variable <em>depends</em> on the independent variable since its often the result from the latter's variations (cases where people developed skin cancer) and finally, the controlled variable is the one that's kept the same throughout the experiment (Time exposed to sunlight within group A or method through which patients were tested for skin cancer).
