|Search:||Browse by Category:|
|Should the value of the indifference (Q) and preference thresholds (P) be in the interval: min |Dc(Ai,Aj)| <= q <= p <= max |Dc(Ai,Aj)| ? where min |Dc(Ai,Aj)| or max |Dc(Ai,Aj)| is the lowest / the highest deviation value for criterion c? So, it won't make sense if we set Q or P out of the interval. Is that right?|
The values of the Q indifference threshold and of the P preference threshold are linked to the evaluations but also to the preferences of the decision-maker. Often on a quantitative criterion there will be at the same time actions that are very close to each other as well as actions with very different evaluations. Let us note Dmin the minimum (>0) deviation and Dmax the maximum deviation. In such a case, Q will probably be larger than Dmin and P smaller than Dmax. But is is not always the case.
Let us consider for instance criterion Price in the Visual PROMETHEE demo example: Dmin = 500€ and Dmax = 23,000€. Probably (except if you are very rich) Q will be smaller than Dmin and P will be smaller than Dmax.
Let us now consider two possible variants:
As a conclusion, values for Q and P can be based on the distribution of the evaluations (that is to some extent what the Preference Function Assistant of Visual PROMETHEE does) but they should be checked according to how the decision-maker perceives the scale of the criterion.
Last update: 12:45 AM Thursday, May 31, 2012
© Bertrand Mareschal, 2011-2013. All rights reserved.