We have developed a system for visualization of visitors' comments as an artwork for exhibitions. The system allows visitors to not only appreciate but participate in an exhibition. The system includes a system for collaborative knowledge construction. Defining a structure of knowledge for representation of data semantics is usually a costly and time-consuming task. Our system is aimed at construction of knowledge with collective intelligence. Users can add resources and properties as they would with social tagging. The system assists the construction of knowledge using suggestions. In this way, the crews tagged attributions to visitors' comments on site and the system visualizes connections among comments as an artwork. We displayed our system in the 14 th Japan Media Art Festival 2011 and 3,100 visitors' comments were tagged on site and visualized as artworks in the festival.