7. Mistakes to avoid

It's never a good idea to have a matrix that's too "incoherent", as this reflects either poor intuition or uncertain expertise on the part of the expert, or in the case of a collegial decision, dissension within the group of experts.

In the first case, there are methods that can indicate the areas of greatest inconsistency within the comparison matrix (see bibliographical references in the "Going further" section) and suggest that the expert minimize or exaggerate certain comparisons (relative to the other comparisons given).

In the second case, there are multi-decision-maker pair comparison methods (see bibliographical references in the "Going further" section) that offer both personal and group convergence functionalities.