Significance of expert competence consideration in group decision making using AHP

The question addressed in the paper is: how does the expert group size influence the importance of experts’ competence consideration while aggregating individual expert judgements using AHP? Some recent studies show that when aggregating direct cardinal and ordinal individual estimates, expert competence does not matter so significantly in cases where the number of expert group members is relatively large (more than 50 experts). The present study is aimed at clarifying the issue in case individual expert judgements are provided as pair comparisons in the fundamental scale and aggregated using AHP methodology. Expert estimates are modelled based on presumptions that they are distributed according to exponential and absolute normal distribution laws. Experiment results confirm the presumption that under large expert numbers, the competence of individual experts matters less significantly but if the number of experts in a group is relatively small, expert competence should always be taken into consideration.