[01] Michael Gr. Voskoglou, Departmentof Applied Mathematics, Faculty of Technological Applications, Graduate Technological Educational Instituteof Western Greece, Patras, Greece. [02] Igor Ya. Subbotin, Department of Mathematics and Natural Sciences, College of Letters and Sciences, National University, Los Angeles, USA.

In the present paper we propose three different fuzzy methods for assessing a system’s performance: The measurement of its total possibilistic uncertainty, the Centre of Gravity (COG) defuzzification technique and the Trapezoidal Fuzzy Assessment Model (TRFAM). Although each one of the above methods can be applied independently, a combined utilization of them helps the user to get a more comprehensive view of the system’s performance, since they compensate for each other. In fact, while the first method is focusing on the system’s mean performance, the last two focus on its quality performance by assigning greater coefficients to the higher scores. Further, the TRFAM, which is a new original variation of the COG technique, treats better the ambiguous cases being at the boundaries between two successive assessment grades. An application (students’ assessment)is also presented illustrating our results, in which the above three fuzzy assessment methods are compared to each other and with two traditional assessment methods based on principles of the bivalent logic (calculation of means and of the GPA index).

System’s Uncertainty, Center of Gravity (COG) Defuzzification Technique, Trapezoidal Fuzzy Assessment Model (TRFAM), Grade Point Average (GPA) Index

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