Tools for shared critical reasoning are the focus for much innovation in
computer supported collaborative learning. Argument diagramming tools allow learners
to create shared graphical depictions of their shared reasoning; celebrated exemplars are
recognized by their distinctive node and link formats. Many evaluations of these tools
have been published, describing their effects on collaboration and learning and offering
explanations of the features and mechanisms that engender better argumentation. It
would be useful then, to review these evaluations to try to discern common themes and
findings, and to understand the different approaches taken. This chapter reviews
significant evaluations of collaborative argumentation diagramming tools, it summarises
important findings about the features of the tools and their effects on collaboration and
learning. The approaches taken in the evaluation of the tools are considered in relation
to their assumptions and aims, methods and outcomes.
Keywords: Evaluation, argument diagram, collaborative learning, abstraction,
argumentation.
