The escalation of disagreement into overt conflict in social interaction can be avoided, if
disagreement is managed through argumentative dialogue. This paper explores the
characteristics of argumentative dialogue and presents the role of third parties who design
spaces for others' dialogue. After discussing the prototypical example of dispute mediators,
this contribution considers other informal third parties who have a similar role. This opens
up a new perspective on informal third parties who work as designers of dialogue and build
spaces to manage disagreement in social interaction.