Preference assessment by imprecise ratio statements

The PAIRS method developed in this paper introduces imprecise preference statements into value trees. The assessment of attribute weights in PAIRS extends the well known SMART technique so that in addition to exact statements the decision maker can enter interval judgments which indicate ranges for the relative importance of the attributes. The interval judgments and the possibly range-valued information about the outcomes of the alternatives are processed with linear programming into value intervals and dominance relations. As the description of the decision maker’s preferences is refined, either by entering new statements or by tightening earlier judgments, these results become more detailed and convey more information about which alternatives are preferred. Throughout the interactive refinement process PAIRS supports the decision maker by deriving and displaying the consequences of earlier judgments.