“…The definitions of power indices try to reflect different aspects of power. Most of them rely on the idea of measuring decisiveness (see [33] [29], [34], [5], [14] or [15] among others), but other aspects like success have also been used ( [31], [18], [9], [7], [8], [35], [24]). There exist another approach, which we call the contextual approach, that takes into account, to measure the power of a voter i, not only the elements N and W but also a probability distribution p over the vote configurations that can emerge.…”