Inter- and Intra-Personal Differences, and Consistency of Decision Rules, in Multi-Criteria Modelling Method DEX: A Preliminary Study.

DEX (Decision EXpert) is a qualitative multi-criteria decision-modelling method in which decision alternatives are evaluated according to decision rules, elicited from individual decision makers. In this preliminary study, we assessed the differences between decision rules acquired from different subjects (inter-personal differences) and from the same subjects at different times (intra-personal differences). We also assessed the consistency of soacquired rules and the ability of subjects to estimate the importance (weights) of criteria. The results indicate a high variability of decision rules, both interand intra-personal. Intra-personal drift is lower than inter-personal differences, but not substantially. The consistency of rules varied between a small decision table with clearly ordered criteria, where it was almost perfect, and a large decision table with less apparent preferential relations, where it was rather poor at the average level of 0.77. Criteria weighs also drifted at the rate 9-19% per month. [ABSTRACT FROM AUTHOR]