Colors are available to distinguish different viewpoints such as different theories or the contribution of each user. Line thickness can be changed to express importance. A primitive freehand drawing tool is also provided to enable users to extend the representational repertory. Labels can be displayed for either shapes or links or both, and users can optionally change the labels and the shapes. The graphical forms we provide for argument representation are loosely based on the analysis developed by the philosopher Stephen Toulmin.
Belvedere is a symbol system for the expression of logical and rhetorical relations within a debate.
We wanted users to focus cognitive effort on the debate rather than on learning to use the program. Thus we made the interface look familiar by using command and icon layouts similar to those of typical drawing programs. We help maintain the students' focus on their understanding of the theories and controversies, rather than on every graphical detail of their diagrams, by automating some of the secondary aspects of the work. For example, graphical shapes are created with a default size, and resize themselves to fit their contents. When an object is moved, its links follow it to retain the logical connection.