Causality in collective filtering

Abstract. In this paper, we describe a proposal for improving the prac-tice of web-based collective filtering, in particular for what regards dis-cussions and selection of issues about policy, based on the intuitive con-cept of causality. Causality, especially when presented in visual form, is especially suited to the task since it is intuitive to understand and to use, and at the same time, it’s rich enough to create a semantic network between the representations of real world facts. We give some examples of the suggested system workflow and we present guidelines for its im-plementation. 1 Collective filtering and why it matters Collective filter platforms are the representative of Web 2.0 in its somewhat purest form. They implement the principles of rating and ranking to present information in a hierarchical way, ordered according measures of relevance and community appreciation. They exploit the participatory practices typical of Web 2.0 to challenge traditional media outlets in the gatekeeping and agenda-settin