Improved minimax disparity model for obtaining OWA operator weights: Issue of multiple solutions

The determination of weights vector is one of the key issues in the theory of ordered weighted averaging (OWA) operators. For this reason, many weight generating models have been proposed in the literature. The main purpose of this note is to point out that the improved minimax disparity model, which is suggested by Emrouznejad and Amin (2010), has infinite solutions. As a consequence, this model is not reliable.