Visualization of argumentation as shared activity

The use of argumentation maps in CSCL does not always provide students with the intended support for their collaboration. In this chapter we compare two argumentation maps from two research projects, both meant to support the collaborative writing of argumentative essays based on external sources. In the COSAR-project, the Diagram-tool with which students could specify positions, proarguments, con-arguments, supports, refutations and conclusions in a free graphical format to write a social studies essay, was highly appreciated by students and teachers, but did not result in better essays. In the CRoCiCL-project, the Debate-tool with which students could specify positions, proarguments, con-arguments, supports and refutations in a structured graphical format, meant to visualize the argumentative strength of the positions, resulted in better history essays. The difference in representational guidance between both tools might explain these differences in effects, with the Debate-tool stimulating students to attend to the justification of positions and their strengths.