  CAT-SD (CATegorization by Similarity-Dissimilarity) is a recently developed
method for handling nominal classification problems in the context of Multiple
Criteria Decision Aiding (MCDA). This paper describes the design and
implementation of this method, as well as an application dealing with a
recruitment process in the Special Forces of the Portuguese Army. In addition,
it proposes interaction protocols to elicit the preference parameters of the
method to facilitate the construction of a decision model when the analyst
guides the decision maker. CAT-SD has been implemented in DecSpace, a
user-friendly on-line platform for supporting decision aiding processes using
one or more MCDA methods. The study related to the Portuguese Army Special
Forces recruitment presents and demonstrates how these protocols and a tool
like DecSpace can facilitate the process of applying the method in real-world
scenarios.
