one that may take on any value in a relationship; for example, in y = f(x), x is the independent variable. For example, independent variables that influence sales are advertising and price.
Advertising research: the independent variable is the element that is subject to arbitrary (not random) change, in order to test the results. For example: If the objective were to test audience response to headline copy, keeping all other factors equal, the sample audience would be subjected to different headline copy to determine the effectiveness of the various headlines. The audience response would be dependent on the stimulus provided-in this case the copy; therefore, the headline copy would be considered the independent variable when it came time to chart the results.
Mathematics and statistics: the factor that is not dependent for change on other factors. For example: if y = 3x, the value of y is always dependent on the value of x, but x can be anything and is therefore the independent variable.
