Cognitive effort is thus not identical with difficulty, motivation, attention, or cognitive control. These features may be necessary, but are yet insufficient to cover the concept.Importantly, effortful tasks are also motivating, sometimes drawing greater engagement when counteracting boredom, or more often causing aversion to engagement, due to someas-yet-unidentified causes. The motivational quality and volitional nature of cognitive effort suggest that anepistemologically useful definition should focus on decision-making: decisions about whether to engage, and also about the intensity of engagement.