An activity produces outcomes and is performed through actions. Nevertheless, the activity cannot be reduced to actions. Rather, an activity is developed throughout the time within a socio-historical process. Individual actions are linked to specific targets or goals that are more or less conscious [12]. In Activity Theory, goals are not fixed. As subjects act, new goals can be formulated or revised from existing goals. Actions are performed through operations. Operations are performed in an automatic, unconscious fashion and are not clearly related to goals. Operations depend on the conditions in which actions are performed. In this context of three levels, Leont'ev proposed structure for an activity as shown in Table 1.