Under CopyrightHufnagel, H.H.HufnagelGeisen, M.M.Geisen2022-03-0302.03.20052004https://publica.fraunhofer.de/handle/publica/20669010.24406/publica-fhg-206690A 3-dimensional virtual classroom that supports synchronous collaborative learning and working is presented. In this environment participants are represented by avatars. They can communicate by audio- or text-chat. In addition, a specific nonverbal repertoire is available. Experiences of preparing, conducting and reinforcing collaborative learning sessions in this environment are described. From these experiences three main tasks of moderating and creating virtual group sessions are derived and their importance is allocated. Specific didactical and psychological aspects are pointed out. Furthermore, it is revealed that the ability of moderating groups can be learned by role change between moderator and single participants in the virtual setting.en004371journal article