Independent variables influence or cause variation in another variable (referred to as the dependent variable). Independent variables are isolated, manipulated, and controlled by a researcher to see how the manipulation affects the dependent variable. Independent variables themselves are not affected or changed by other variables; their existence is not dependent on other variables in the proposed relationship. Also referred to as predictor variable, the independent variable is an essential component of quantitative research designs, as it is the catalyst for the measurable changes in a research study. This entry describes qualities of independent–dependent variable relationships, provides basic examples, and lists common statistical approaches for variable relationship analysis.

To test study predictions, a researcher looks to see if a dependent variable changes based on ...