In
statistics, a
mediation model is one that seeks to identify and explicate the mechanism or process that underlies an observed relationship between an
independent variable and a
dependent variable via the inclusion of a third hypothetical variable, known as a
mediator variable (also a
mediating variable,
intermediary variable, or
intervening variable). Rather than a direct causal relationship between the independent variable and the dependent variable, a mediation model proposes that the independent variable influences the (non-observable) mediator variable, which in turn influences the dependent variable. Thus, the mediator variable serves to clarify the nature of the relationship between the independent and dependent variables.