: Computer-mediated environments provide an arena for learning to argue. We investigate to what extent student dyads’ online argumentation can be facilitated with collaboration scripts that (1) prompt learners to prepare individually, (2) create conflict, and (3) encourage productive collaboration and argumentation. A process analysis of the chats of the dyads showed that the scripted treatment group used significantly more words and broadened and deepened their discussions significantly more than the unscripted group. Qualitative analysis indicates that scripted learners engaged in more critical and objective argumentation than non-scripted learners.