The final metric rating of the assessments given to a user i by other users in the proposal is computed through ari, the average of all the ratings received by i measured in points. A user who has been using the system for a while normally would have more ratings than a recent user, unless the behaviour of the first user has been incorrect. Thus, the way the proposed system can compare the performance of both users is by averaging their ratings because, otherwise, if the simple sum of ratings were used, the user who has been using the system longer would always have more points than a recent one, although the recent one has had a better behaviour or performance.