@inproceedings { prada05, abstract = {Today, many interactive games and virtual communities engage several users and intelligent virtual agents (IVAs) all interacting in the same virtual environment, which additionally, may present collaborative tasks to the participants. The success of the interactions relies on the ability of the agents to meet the user’s expectations, thus, showing a coherent and believable set of behaviours. For this reason, in scenarios where users and IVAs interact as a group, it is very important that the interactions follow a believable group dynamics. Focusing on this problem, we have developed a model that supports the dynamics of a group of IVAs, inspired by theories of group dynamics developed in human social psychological sciences. The dynamics is driven by a characterization of the different types of interactions that may occur in the group. The model was implemented in a computer game that engage the user with a group of four IVAs in the resolution of collaborative tasks. This game was used in an evaluation experiment which showed that the model had a positive effect on the users’ social engagement in the group, namely on their trust and identification with the group.}, address = {Kos - Grécia}, booktitle = {IVA'2005 - 5th International Conference on Intelligent Virtual Agents}, keywords = {group dynamics, teamwork, social intelligence, autonomous synthetic characters, believability, computer–human interaction}, month = {September}, pages = {317-328}, publisher = {Springer Berlin / Heidelberg}, series = {Lecture Notes in Computer Science}, title = {Intelligent Virtual Agents in Collaborative Scenarios}, volume = {3661/2005}, year = {2005}, author = {Rui Prada and Ana Paiva} }