1 COllaborative Virtual ENvironments: Experiments on Small Group Behaviour in the COVEN Project Jolanda Tromp 1 , Anthony Steed 2 , Emmanuel Frécon 3 , Adrian Bullock 1 , Amela Sadagic 2 , Mel Slater 2 Abstract This paper describes work being undertaken by the multi-partner European Union funded project COVEN (COllaborative Virtual ENvironments). COVEN is developing collaborative virtual environment (CVE) systems and technologies in order to support a group of travel rehearsal applications. One of the major themes of the project is the evaluation of CVE applications through extensive network trials, usability evaluations and in depth case-controlled experiments. This paper concentrates upon an experimental study where groups of three strangers meet in a CVE to carry out a simple collaborative task. The experiment was designed to investigate issues about group behaviour such as the relationship between emergent leadership and computational resources, presence of being in a place, and the co-presence, the sense of togetherness, amongst the participants. This experiment and others undertaken by the project highlight a number of issues to do with participant representation, interaction style and system implementation that need to be addressed in future CVE development. Keywords Virtual reality, collaborative virtual environments, user evaluation, small group behaviour, presence 1. Introduction The Collaborative Virtual Environments (COVEN) project, is a four year European project that was launched in October 1995, to design and explore collaborative virtual environment (CVE) technology. Its aim is to investigate the feasibility of scaleable CVE worlds through the development of CVE systems development and the demonstration of prototype applications in the area of virtual travel rehearsal. We work from the premise that there will always be a limit to available computing and communications resources with resulting tradeoffs between realism and interactive performance. As a result, we prioritize specific user and application needs and then find ways of supporting them within a limited computing resource. Thus our approach to design has started with relatively simple worlds and embodiments, while incrementally 1 University of Nottingham, UK 2 University College London, UK 3 Swedish Institute of Computer Science