Multi-user multi-account interaction in groupware supporting single-display collaboration

Combining support for single display collaboration with support for asynchronous and remote collaboration in one groupware challenges some basic assumptions of application design and brings up new requirements for application platforms. While user accounts are central in many kinds of groupware, they are not respected in groupware support for multi-user single-screen interaction. Current support for this interaction paradigm does not allow users to act on their own behalf; they have to act on behalf of a host user. We suggest an approach to distinguish the interactions with different users in multi-user single-screen scenarios. Our approach enables applications to link actions to the acting user's account. We describe the integration of suggested concepts in the groupware ProjectTalk, an application for managing XP projects that supports multi-user single-screen interaction. All interacting users are allowed to work with ProjectTalk on their own behalf.