Mediators of goal effects. Goal effects are mediated most directly by three
relatively automatized mechanisms: (1) focus of attention on the desired end
state to the exclusion of other goals, (2) regulation of physical as well as
cognitive effort (Wegge and Dibbelt, 2000) in proportion to what is required
to attain the goal, and (3) persistence of effort through time until the goal is
attained. The role of a fourth mediator, task knowledge or skill, is more
complex (Locke, 2000). A goal cannot be attained unless the individual
knows how to do so. We will have more to say about this later