Argumentation scheme and shared online diagramming in case-based collaborative learning

Argumentation schemes describe patterns of reasoning in discourse. We report an investigation into whether the argumentation scheme known as 'inference to the best explanation' (IBE) captures the argumentation found in collaborative case-based learning. We examine the dialogue of three students working in an online learning environment as they attempt to explain the verdict in a legal case of medical negligence; the IDE scheme is clearly visible in the dialogue. We also report the exploratory development of shared argument diagramming tools that allow learners to draw their explanations while they discuss them. The tools passively reinforce the IBE argumentation scheme. Evaluation of the tools provided the clearest evidence to date that learners are able to integrate their shared online argument diagramming with their computer-mediated dialogue.