Independent Variable

Independent variable is complementary to dependent variable. These two concepts are used primarily in their mathematical sense, meaning that the value of a dependent variable changes in response to that of an independent variable. In research design, independent variables are those that a researcher can manipulate, whereas dependent variables are the responses to the effects of independent variables. By purposefully manipulating [Page 592]the value of an independent variable, one hopes to cause a response in the dependent variable.

As such, independent variables might carry different names in various research fields, depending on how the relationship between the independent and the dependent variable is defined. They might be called explanatory variables, controlled variables, input variables, predictor variables, factors, treatments, conditions, or other names. For instance, in regression ...