Abstract
In regard to the multipurpose problem involving multiple stakeholders in decision making, transparency in the decision making process is required to promote smooth consensus formation. In this research, assuming the mid-confirmed contamination restoration project at the illgal dumping site, whitch is a multi-subject multi-object problem, construct an evaluation structure model to select the restoration goal and alternative plan and analyze it using the ANP method. Individual evaluation weights are calculated based on the analysis results, and grouped evaluators. By giving additional information to the evaluators, I revealed the attitude change of the evaluators. I introduced a measure of the degree of aggregation, developed a method to quantitativerly visualize the change of aggregation as a whole, and showed possibility to grasp not only a large number of opinions but also a small number of opinions at the discussion place.
