This article reports on argumentation as a crucial communicative activity in society. There are many available technologies that support argumentation, such as mailing lists, group decision-support systems, coauthoring, and negotiation support systems. However, many of these technologies do not work well in practice, and they often support discussions that do not sufficiently contribute to the purposes of their users. The authors examine how to select or design information technologies to better support the argumentative practices of their community of use.