Describe three specific applications of the factorial design: (1) adding a factor to an existing study; (2) using a participant variable as a second factor to control the variance in a...

Describe three specific applications of the factorial design: (1) adding a factor to an existing study; (2) using a participant variable as a second factor to control the variance in a between-subjects design; and (3) using the order of treatments as a second factor to evaluate the order effects in a within-subjects design; explain the advantage of using a factorial design in these situations.