Aggregation of Ordinal Information in Decision Making

We extend a multiple expert, multiple criteria decision aiding technique on an ordinal evaluation scale, originally proposed by Yager. This extension is heavily based on the definition of logic and averaging operators on such scales. We can show a variety of these operations, so the decision maker can have some freedom in choosing the most appropriate one for his/her special purpose. In particular, the case of smooth underlying operators (t-norms and t-conorms) is handled with special emphasis. The applicability of the results is illustrated by an example.