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2003, International Journal of Approximate Reasoning
The more information a preference structure gives, the more sophisticated representation techniques are necessary, so decision makers can have a global view of data and therefore a comprehensive understanding of the problem they are faced with. In this paper we propose to explore valued preference relations by means of a search for the number of underlying criteria allowing its representation in real space. A general representation theorem for arbitrary crisp binary relations is obtained, showing the difference in representation between incomparability--related to the intersection operator--and other inconsistencies--related to the union operator. A new concept of dimension is therefore proposed, taking into account inconsistencies in source of information. Such a result is then applied to each a-cut of valued preference relations.
Translation of Classical Dimension Theory into a valued context should allow a comprehensible view of alternatives, by means of an informative representation, being this representation still manageable by decision makers. In fact, there is an absolute need for this kind of representations, since being able to comprehend a valued preference relation is most of the time the very first difficulty decision makers afford, even when dealing with a small number of alternatives. Moreover, we should be expecting deep computational problems, already present in classical crisp Dimension Theory. A natural approach could be to analyze dimension of every α-cut of a given valued preference relation. But due to complexity in dealing with valued preference relations, imposing max-min transitivity to decision makers in order to assure that every α-cut defines a crisp partial order set seems quite unrealistic. In this paper we propose an alternative definition of crisp dimension, based upon a general representation result, that may allow the possibility of skipping some of those computational problems.
International Journal of General Systems, 2004
Representation of binary preference relations in a real space where each coordinate suggests the existence of underlying criteria is a standard and indeed suggestive approach. Classical dimension theory addresses this problem, showing that whenever crisp preferences define a partial order set, it can be represented in a real space, and then we can search for a minimal representation. Valued preference relation being a much more complex structure, there is an absolute need for meaningful representations, being manageable by decision-makers. In this paper, we continue analyzing the concept of a generalized dimension function of valued preference relations, i.e. a mapping assigning a generalized dimension value to every a-cut of any given valued preference relation, as introduced in a previous paper. We should of course be expecting deep computational problems within this generalized dimension context, since they are already present in crisp dimension theory. In this paper, we present some properties of such a generalized dimension function, pointing out that our approach allows alternative representations depending on some underlying rationality core the decision-maker may change.
Journal of Multi-Criteria Decision Analysis, 1995
This paper is concerned with procedures which transform valued preference relations on a set of alternatives into crisp relations. We present a simple characterization of a procedure that ranks alternatives in decreasing order of their minimal performance. This is done by means of three axioms that are shown to be independent. Among other results, we characterize in a very similar manner a procedure called 'leximin' and investigate two families of procedures whose intersection is the 'min' procedure. KEY WORDS Multicriteria decision Preference modelling Valued preference relations Fuzzy sets
Journal of Interdisciplinary Mathematics, 2004
In decision theory several preference structures are used for modeling coherence and rational behavior. In this paper we establish, from an algebraic approach, characterizations of some general properties involving preference and indifference relations, as well as the more common preference structures used in the literature.
Journal of Mathematical Economics, 2011
We develop the ordinal theory of (semi)continuous multi-utility representation for incomplete preference relations. We investigate the cases in which the representing sets of utility functions are either arbitrary or finite, and those cases in which the maps contained in these sets are required to be (semi)continuous. With the exception of the case where the representing set is required to be finite, we find that the requirements of such representations are surprisingly weak, pointing to a wide range of applicability of the representation theorems reported here. Some applications to decision theory under uncertainty and consumer theory are also considered.
Theoria, 2008
The paper provides a general account of value relations. It takes its departure in a special type of value relation, parity, which according to Ruth Chang is a form of evaluative comparability that differs from the three standard forms of comparability: betterness, worseness and equal goodness. Recently, Joshua Gert has suggested that the notion of parity can be accounted for if value comparisons are interpreted as normative assessments of preference. While Gert's basic idea is attractive, the way he develops it is flawed: His modeling of values by intervals of permissible preference strengths is inadequate. Instead, I provide an alternative modeling in terms of intersections of rationally permissible preference orderings. This yields a general taxonomy of all binary value relations. The paper concludes with some implications of this approach for rational choice.
Dimension Theory allows the representation of any finite set of alternatives in a real space, provided that the associated preference relation defines a partial order set. Such a representation can be very useful whenever criteria are not known, are therefore we can not even address the problem of evaluating their respective weights. In this paper we propose that the importance of underlying criteria can be approached taking into account those possible representations associated to the dimension of the binary preference relations between criteria.
European Journal of Operational Research, 2000
The classical notion of dimension of a partial order can be extended to the valued setting, as was indicated in a particular case by Ovchinnikov (Ovchinnikov, S.V., 1984. Representations of transitive fuzzy relations. In: Skala, H.J., Termini, S., Trillas, E. (Eds.), Aspects of vagueness. Reidel, Boston, pp. 105±118). Relying on Valverde's result (1985) (Valverde, L., 1985. On the structure of F-indistinguishability operators. Fuzzy Sets and Systems 17, 313± 328) on the transitive closure of a valued relation, we de®ne the dimension of a valued quasi order. Building then on Fodor and Roubens (1995) (Fodor, J., Roubens M., 1995. Structure of transitive valued binary relations. Mathematical Social Sciences, 30, 71±94), we also show that the de®nition can be generalized to all valued relations by using valued biorders instead of valued weak orders as one-dimensional relations. Interesting, combinatorial questions about the new dimension concept arise and are investigated here. In particular, we aim at a characterization of valued quasi orders of dimension two. Ó
Theory and Decision, 1974
An axiomatic system TP is developed which allows the amalgamation of linear preferences (preferences in respect to different criteria) according to the weights of those criteria. Section 1 deals with linear preferences. In Section 2 an axiomatic system for the ordering of classes of criteria is formulated. Section 3 explains the development of system TP. Two TP-systems are distinguished, based on two different linear preference systems. The preference relation of TP is shown to be nontransitive, while the linear preference relation is transitive. In 3.7 an alternative-system TP' is given. Section 3.8 deals with formulas concerning the disjunction of alternatives, which are not valid in TP, even though they are valid in a linear preference system. In Section 4 types of preference relations and types of alternatives are distinguished to get the opportunity to express preferences between preferences.
2000
Let X = {X i } be a set of variables, each with a domain D i . An outcome α ∈ O is a complete assignment to all the variables, denoted by the tuple α := α(X 1 ), α(X 2 ), . . . , α(X m ) such that α(X i ) ∈ D i for each X i ∈ X . The set of all possible outcomes is given by O = Xi∈X D i . We consider a preference language L for specifying: (a) unconditional intra-variable preferences ≻ i that are strict partial orders (i.e., irreflexive and transitive relations) over D i ; and (b) unconditional relative importance preferences that are strict partial orders over X .
European Journal of Operational Research, 1992
In this paper we study a particular method that builds a partial ranking on the basis of a valued preference relation. This method which is used in the MCDM method PROMETHEE I, is based on "leaving" and "entering" flows. We show that this method is characterized by a system of three independent axioms.
MICAI 2004: Advances in …, 2004
Fuzzy (valued) preference relations (FPR) give possibility to take into account the intensity of preference between alternatives. The refinement of crisp (non-valued) preference relations by replacing them with valued preference relations often transforms crisp preference relations with cycles into acyclic FPR. It gives possibility to make decisions in situations when crisp models do not work. Different models of rationality of strict FPR defined by the levels of transitivity or acyclicity of these relations are considered. The choice of the best alternatives based on given strict FPR is defined by a fuzzy choice function (FCF) ordering alternatives in given subset of alternatives. The relationships between rationality of strict FPR and rationality of FCF are studied. Several valued generalizations of crisp group decision-making procedures are proposed. As shown on examples of group decision-making in multiagent systems, taking into account the preference values gives possibility to avoid some problems typical for crisp procedures.
Journal of logic and …, 2002
The paper is a theoretical study of a generalization of the lexicographic rule for combining ordering relations. We define the concept of priority operator: a priority operator maps a family of relations to a single relation which represents their lexicographic combination according to a certain priority on the family of relations. We present four kinds of results.
Mathematical Social Sciences, 1995
We consider a class of relations which includes irreflexive preference relations and interdependent preferences. For this class, we obtain necessary and sufficient conditions for representation of the relation by two numerical functions in the sense of a ~ x if and only if u(a) < vex).
2007
We introduce two criteria for judging "goodness" of the result when combining preference relations in information systems: completeness and consistency. Completeness requires that the result must be the union of all preference relations, while consistency requires that the result must be an acyclic relation. In other words, completeness requires that the result contain all pairs appearing in the preference relations, and only those pairs; while consistency requires that for every pair (x, y) in the result, it must be able to decide which of x and y is preferred to the other. Obviously, when combining preference relations, there is little hope for the result to satisfy both requirements. In this paper, we classify the various methods for combining preference relations, based on the degree to which the result satisfies completeness and consistency. Our results hold independently of the nature of preference relations (quantitative or qualitative); and also independently of the preference elicitation method (i.e. whether the preference relations are obtained by the system using query-log analysis or whether the user states preferences explicitly). Moreover, we assume no constraints whatsoever on the preference relations themselves (such as transitivity, strict ordering and the like).
2015
We consider the problem of normalizing the priority vectors associated with fuzzy preference relations and we show that a widely used normalization procedure may lead to unsatisfactory results whenever additive consistency is involved. We give some examples from the literature and we propose an alternative normalization procedure which is compatible with additive consistency and leads to better results.
2015
summary:In decision processes some objects may not be comparable with respect to a preference relation, especially if several criteria are considered. To provide a model for such cases a poset valued preference relation is introduced as a fuzzy relation on a set of alternatives with membership values in a partially ordered set. We analyze its properties and prove the representation theorem in terms of particular order reversing involution on the co-domain poset. We prove that for every set of alternatives there is a poset valued preference whose cut relations are all relations on this domain. We also deal with particular transitivity of such preferences
Journal of Mathematical Economics, 2013
A classical approach to model a preference on a set A of alternatives uses a reflexive, transitive and complete binary relation, i.e. a total preorder. Since the axioms of a total preorder do not usually hold in many applications, preferences are often modeled by means of weaker binary relations, dropping either completeness (e.g. partial preorders) or transitivity (e.g. interval orders and semiorders). We introduce an alternative approach to preference modeling, which uses two binary relations -the necessary preference N and the possible preference P -to fulfill completeness and transitivity in a mixed form. Formally, a NaP-preference (necessary and possible preference) on A is a pair
In practical decision-making, it seems clear that if we hope to make an optimal or at least defensible decision, we must weigh our alternatives against each other and come to a principled judgment between them. In the formal literature of classical decision theory, it is taken as an indispensable axiom that cardinal rankings of alternatives be defined for all possible alternatives over which we might have to decide. Whether there are any items " beyond compare " is thus a crucial question for decision theorists to consider when constructing a formal framework. At the very least, it seems problematic to presuppose that no such incommensurability is possible on the grounds that it would make formalizing axioms for decision-making more difficult, or even intractable. With this in mind, I plan to argue in this paper that a formal notion of comparability can be introduced to the classical understanding of preference relations such that the question of comparability between alternatives can be taken non-trivially. Building on the work of Richard Bradley and Ruth Chang, I argue that the comparability relation should be understood to be transitive but not complete. I contend that this understanding of comparability within decision theory can explain both why we believe that some alternatives may be incommensurable, yet we are still able to make justified decisions despite incomplete preference relations. In Section I, I lay the groundwork for understanding the conceptual relationship between comparability and commensurability with respect to decision-making. In Section II, I will argue that Bradley's definition of the preference relation with comparability leads to absurdity and contradiction due to a small oversight, which I propose to remedy. Then,
In decision making, consistency in fuzzy preference relations is associated with the study of transitivity property. While using additive consistency property to complete incomplete preference relations, the preference values found may lie outside the interval [0, 1] or the resultant relation may itself be inconsistent. This paper proposes a method that avoids inconsistency and completes an incomplete preference relation using an upper bound condition. Additionally, the paper extends the upper bound condition for multiplicative reciprocal preference relations. The proposed methods ensure that if (n − 1) preference values are provided by an expert, such that they satisfy the upper bound condition, then the preference relation is completed such that the estimated values lie inside the unit interval [0, 1] in the case of preference relations and [1/9, 9] in the case of multiplicative preference relation. Moreover, the resultant preference relation obtained using the proposed method is transitive.
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