The decision-making paradox is a phenomenon related to
decision-making
In psychology, decision-making (also spelled decision making and decisionmaking) is regarded as the cognitive process resulting in the selection of a belief or a course of action among several possible alternative options. It could be either r ...
and the quest for determining reliable decision-making methods. It was first described by Triantaphyllou , and has been recognized in the related literature as a fundamental paradox in multi-criteria decision analysis (MCDA), multi-criteria decision making (MCDM) and
decision analysis Decision analysis (DA) is the discipline comprising the philosophy, methodology, and professional practice necessary to address important decisions in a formal manner. Decision analysis includes many procedures, methods, and tools for identifying, ...
since then.
Description
The decision-making paradox was first described in 1989,
and further elaborated in the 2000 book by Triantaphyllou on
multi-criteria decision analysis
Multiple-criteria decision-making (MCDM) or multiple-criteria decision analysis (MCDA) is a sub-discipline of operations research that explicitly evaluates multiple conflicting criteria in decision making (both in daily life and in settings ...
(MCDA) / multi-criteria decision making (MCDM).
It arises from the observation that different decision-making methods, both normative and descriptive, yield different results, when fed with exactly the same decision problem and data.
It has been recognized in the related literature as a fundamental paradox in multi-criteria decision analysis (MCDA) / multi-criteria decision making (MCDM), and
decision analysis Decision analysis (DA) is the discipline comprising the philosophy, methodology, and professional practice necessary to address important decisions in a formal manner. Decision analysis includes many procedures, methods, and tools for identifying, ...
since then.
In a study reported in ''International Journal of Decision Support Systems''
and ''Multi-Criteria Decision Making: A Comparative Study'',
the following investigation was undertaken. Since in the beginning it was assumed that the best method is not known, the problem of selecting the best method was solved by successively using different methods. The methods used in that study were the
weighted sum model
In decision theory, the weighted sum model (WSM),
also called weighted linear combination (WLC) or simple additive weighting (SAW),
is the best known and simplest multi-criteria decision analysis (MCDA) / multi-criteria decision making method ...
(WSM), the
weighted product model (WPM), and two variants of the
analytic hierarchy process (AHP). It was found that when a method was used, say method X (which is one of the previous four methods), the conclusion was that another method was best (say, method Y). When method Y was used, then another method, say method Z, was suggested as being the best one, and so on.
Two evaluative criteria were used to formulate the previous decision-making problem, which is actually an
MCDM problem. The first criterion was based on the premise that a method which claims to be accurate in multi-dimensional problems (for which different units of measurement are used to describe the alternatives), should also be accurate in single-dimensional problems. For such problems, the
weighted sum model
In decision theory, the weighted sum model (WSM),
also called weighted linear combination (WLC) or simple additive weighting (SAW),
is the best known and simplest multi-criteria decision analysis (MCDA) / multi-criteria decision making method ...
(WSM) is the widely accepted approach, thus, their results were compared with the ones derived from the WSM.
The second evaluative criterion was based on the situation: alternative A, is evaluated as the best alternative, compared to the non-optimal alternative B. If B is replaced by a worse one, one should expect that alternative A remains the best alternative, under normal conditions where the weights of the two evaluative criteria in all possible combinations always add equal to 1. If not it is known as a
ranking reversal.
Methods affected
The following
multi-criteria decision-making methods have been confirmed to exhibit this paradox:The
analytic hierarchy process (AHP) and some of its variants, the
weighted product model (WPM), the
ELECTRE (outranking) method and its variants and the TOPSIS method.
Other methods
Other methods that have not been tested yet but may exhibit the same phenomenon include the following:
* The
analytic network process (ANP).
* The
PROMETHEE (outranking) method.
*
Ordinal Priority Approach (OPA)
*
Multi-attribute utility theory (MAUT).
*
Dominance-based rough set approach (DRSA)
*
Aggregated indices randomization method (AIRM)
* Nonstructural fuzzy decision support system (NSFDSS)
*
Grey relational analysis Grey relational analysis (GRA) was developed by Deng Julong of Huazhong University of Science and Technology. It is one of the most widely used models of grey system theory. GRA uses a specific concept of information. It defines situations with no i ...
(GRA)
*
Superiority and inferiority ranking method (SIR method)
*
(PAPRIKA)
*
Value analysis (VA)
A key role in this quest is played by the study of
rank reversals in decision making
In decision-making, a rank reversal is a change in the rank ordering of the preferability of alternative possible decisions when, for example, the method of choosing changes or the set of other available alternatives changes. The issue of rank re ...
.
References
{{Decision theory paradoxes
Decision-making paradoxes