In this article we propose a novel approach for group-decision making, i.e., proposing and selecting solutions to issues discussed in online settings, based on the structure of the discussion. Our approach consists of three steps: (1) assigning weights to participants based on formal criteria such as degree of engagement in the discussion; (2) assigning scores to comments, considering the weights of authors and raters; (3) assigning scores to proposals, based on the scores of the pro and contra arguments. An important point is that individuals whose behavior is in line with our formal criteria have a higher influence on the decisions. Having built a respective online platform, we have evaluated the proposed model by means of an experiment with more than 100 participants who have discussed several topics relevant to them and a subsequent survey. Looking at both the results of survey and the discussion outcomes, we conclude that our approach yields comprehensive discussions and outcome decisions supported by the community.
