Likert Scales in Group Multiple-criteria Evaluation
Jan Stoklasa, Tomáš Talášek, Jaroslava Kubátová and Klára Seitlová
Likert scales are a widely used tool for attitude expression in many fields of social science. In this paper we explore their use in multiple-criteria multi-expert evaluation. We propose a methodology that deals with the non-uniformity of the distribution of linguistic labels along the evaluation universe and also with possible response bias (central tendency and extreme-response tendency). The methodology represents the Likert-type evaluations of an alternative with respect to various criteria using histograms. Histograms are used in the process of aggregation of information, since the underlying evaluation scale is ordinal. A transformation of the multi-expert multiple-criteria evaluation represented by a histogram into a 3-bin histogram to control for the response bias is performed and an ideal-evaluation 3-bin histogram is defined. We propose a distance measure to assess the closeness of the overall evaluation to the ideal and suggest the use of its values in interpretation/ evaluation fuzzy rules.
Keywords: Likert scale, histogram, distance, evaluation, MCDM, group evaluation.