A spatial version of the Shang method

This paper proposes a modified version of the Shang method, starting from the assumption that the convergence of opinions involves a spatial context in many applications. The Spatial Shang we present is based, like the classical Shang method, on judgments of a panel of experts, and is applicable when consultations and consequent decisions concern matters of spatial location. The experts are first asked to draw four points on a map while, in subsequent rounds, each panelist must locate a single point, representing her/his evaluation, in one of four rectangles drawn on the map. The method is very easy to be implemented and the whole procedure is very fast to be performed. The application presented in this paper concerns the Costa Teatina National Park (Italy) and the definition of its boundaries. We will here present the on-going conflict and the contribution to its mitigation offered by the Spatial Shang method. The application resulted in a convergence of opinions in a buffer of 550 m; that can be used as a decision support for the choice on the best location for the park's boundaries.