This study involved a teaching experiment in which academic argumentation was practiced during a ten-week email course in a Finnish university. During the course, two working methods were used: free debate and role play. The aim of the study was to clarify how these two working methods activated students in mutual argumentative dialogue and affected its quality. The research questions were: (1) "How interactive were the students' messages?"; (2) "How argumentative was the interaction?"; (3) "What roles did the students assume during the interaction?"; and (4) "Was the quantity and quality of interaction affected by working method and gender?" An analysis of students' messages indicated that most (78 percent) were interactive, but most of those only involved two students. Most messages took a neutral position. Thus, findings suggested that one of the tasks of the course, to encourage students to engage in active argumentative discussion with contributions by many students, was not satisfactorily achieved. Role playing increased argumentation, and gender differences were noted. (Contains 17 references.) (EV)