the practical benefits for varied practice in the educational domain may be largely untapped. dempster and corkill (1999) argued that the available evidence warranted focused investigations of the role of these underlying processes (cognitive inhibition and contextual interference) to the teaching-learning process. more recently, rohrer and his colleagues studied the benefits of varied practice in mathematics curricula. rohrer and taylor (2007) noted that, contrary to the basic science supporting the varied practice approach, most mathematics textbooks had each set of practice sections made up almost entirely of problems corresponding to the immediately previous lesson; only in a small number of cases did they find the practice problems to be systematically shuffled so that each practice set includes a variety of problems drawn from many previous lessons. they concluded that varied practice was underused.