Reflections on Common Misunderstandings When Using AHP and a Response to Criticism of Saaty’s Consistency Index



Published Dec 6, 2018
Claudio Garuti


This essay deals with misunderstandings which, in this author’s opinion, seem to prevail in the minds of some AHP critics. The main apparent problem is the lack of necessary knowledge about the scale concept including what a scale is, how it is mathematically defined, and what one can or cannot do with a scale. This knowledge is critical for a good understanding of AHP. This study will review the concept of scales, discuss common misconceptions, introduce the compatibility index G and explain how it addresses one of the previous fallacies perpetuated about AHP.


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AHP misconceptions, scales, compatibility index

Garuti, C. (2012). Measuring in weighted environments: Moving from metric to order topology. In F. De Felice, A. Petrillo, T. Saaty (Ed.), Applications and Theory of Analytic Hierarchy Process - Decision Making for Strategic Decisions (pp. 247-275) Santiago, Chile: Universidad Federico Santa Maria. Doi: 10.5772/63670

Garuti, C. (2014b). Compatibility of AHP/ANP vectors with known results. ISAHP2014

Garuti, C., Salomon, V., Spencer, I. (2008). A systemic rebuttal to the criticism of using the eigenvector for priority assessment in the Analytic Hierarchy Process for decision making. Computación y Sistemas (Review), 12(2), 192-207.

Garuti, C Escudey M. (2005). Toma de decisiones en escenarios complejos. Santiago-Chile: Editorial Universidad de Santiago Publications.

Jaccard, P. (1901). Distribution de la flore alpine dans le basin des dranses et dans quelques regions voisines. Bulletin de la Société Vaudoise des Sciences Naturelles 37, 241-272. Doi:

Mahalanobis, P.C., (1936). On the generalized distance in statistics. Proceedings of the National Institute of Science of India, 12, 49-55.

Saaty, L.T. (2001). The Analytic Network Process: Decision making with dependence and feedback. Pittsburgh, PA: RWS Publications.

Saaty, L.T. (2010). Group decision making: Drawing out and reconciling differences. Pittsburgh, PA: RWS Publications. Doi:

Koczkodaj, W.W., Szybowski, J. (2015). On the convergence of the pairwise comparisons inconsistency reduction process.
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