DS/AHP was introduced in Beynon, Curry, and Morgan (2000) and Beynon (2002a), and is a nascent method of multi-criteria decision support. Following a hierarchical decision structure, similar to the analytic hierarchy process— AHP (Saaty, 1980), the identification of groups of alternatives (DAs) against the whole set of alternatives considered, over a number of different criteria, is operationalised using Dempster-Shafer theory—DST (Dempster, 1968; Shafer, 1976). As such, the utilisation of DS/AHP means the decision making is embedded with the realisation of the presence of ignorance and non-specificity in the decision judgements made (see Beynon, 2005). Studies have acknowledged that the making of decisions is often difficult because of uncertainty and conflict in the judgement making process (Shafir, Simonson, & Tversky, 1993). Nutt (1998) references that a key incumbent in decision making is complexity, which prompts difficult decisions as well as manifesting how daunting a decision may appear. The notion of ignorance prevalent within DS/AHP, from DST, has been described as a general term for incompleteness, imprecision, and uncertainty (Smets, 1991), also relating to the subjective imperfection of a decision maker (Motro & Smets, 1997).
Key Terms in this Chapter
AHP: The technique analytic hierarchy process to aid multi-criteria decision making.
Non-Specificity: In Dempster-Shafer theory, the weighted average of the focal elements’ mass values in a body of evidence, viewed as a species of a higher uncertainty type, encapsulated by the term ambiguity.
Pignistic Probability: In Dempster-Shafer theory, a measure to dissipate the mass values associated with focal elements to a specified focal element.
Dempster-Shafer Theory: General methodology, whose rudiments are closely associated with uncertain reasoning.
Body of Evidence: In Dempster-Shafer theory, a series of focal elements and associated mass values.
Frame of Discernment: In Dempster-Shafer theory, the set of all hypotheses considered.
Mass Value: In Dempster-Shafer theory, the level of exact belief in a focal element.
Focal Element: In Dempster-Shafer theory, a set of hypothesis with positive mass value in a body of evidence.
Belief: In Dempster-Shafer theory, the level of representing the confidence that a proposition lies in a focal element or any subset of it.
Plausibility: In Dempster-Shafer theory, the extent to which we fail to disbelieve a proposition lies in a focal element.
Ignorance: In Dempster-Shafer theory, the level of mass value not discernible among the hypotheses.