Science and Education Publishing American Journal of Applied Mathematics and Statistics 2328-7292 2 1 2013 12 27 Measuring the Uncertainty of Human Reasoning 1 6 EN Michael Gr. Voskoglou School of Technological Applications, Graduate Technological Educational Institute (T. E. I.) of Western Greece, Patras, Greece AJAMS2014211 10.12691/ajams-2-1-1 2013 11 15 2013 12 12 2013 12 27 Human reasoning is characterized by a degree of fuzziness and uncertainty. In the present paper we develop a fuzzy model for a better description of the reasoning process and we use the fuzzy systems' total possibilistic uncertainty as well as the classical 's entropy (properly modified for use in fuzzy environments) in measuring the individuals' reasoning skills. Classroom experiments are also provided illustrating our results in practice.