A dependent variable is a variable whose value depends on the values of one or more other independent variables. This notion comes up regularly in a variety of contexts. In the case of a univariate function y = f(x), the dependent variable is y since its value is directly dependent upon the value of the independent variable x. For multivariate functions y = f(x_1, ..., x_n), the value of the variable y depends on the values of the independent variables x_1, ..., x_n. In an experiment, the dependent variable generally represents the output whose values were altered by causal phenomena--represented by independent variables--in the experiment.