AN ALTERNATIVE FRAMEWORK FOR DEFINING MEDIATION

The present article provides an alternative framework for evaluating m ediated relationships. From this perspective, a mediated process is a chain reaction, beginning with an independent variable that affects a mediator that in turn affects an outcome. The definition of mediation offered here, presented for stage sequences, states three conditions f or establishing mediation: (a) the independent variable affects the pr obability of the sequence no mediator to mediator Co outcome; (b) the independent variable affects the probability of a transition into the mediator stage; (c) the mediator affects the probability of a transiti on into the outcome stage at every level of the independent variable. This definition of mediation is compared and contrasted with the well- known definition of mediation for continuous variables discussed in Ba ron and Kenny(1986), Judd and Kenny (1981), and Kenny, Kashy, and Bolg er (1997). The definition presented in this article emphasizes the int raindividual, time-ordered nature of mediation.