WikiGIS is a map-based platform that allows participants to contribute local knowledge. It is similar to traditioanal Wiki page, where everyone can contribute in shaping the description of a certain location, adding text and media. In addition to this function of traditional Wiki, WikiGIS provides a map-based tool that allows participants to view/input/edit geometric and descriptive components (points, polylines, polygons, and comments). Various descriptions of the location will finally form a concensus, which makes this method a converging method. Every edit in the content is recorded and can be traced. By tracking these changes, users can see the not only the geographical changs of the area but also the changes of people’s description/perception of it.