The goal of this thesis is to present the virtual environments research community with a thorough investigation of collaborative awareness in Tele- immersion and related immersive virtual environments. Tele-immersion was originally defined in 1996 by Tom Defanti of the Electronic Visualization Laboratory (EVL), is "the union of networked VR and video in the context of significant computing and data mining" [Leigh, et. al., 1997]. Since then, research on Tele-immersion has outgrown most of its system and performance-related issues and now focuses supporting collaborative interaction and usability. Tele-immersion now deals with the "[creation of persistent virtual environments] enabling multiple, globally situated participants to collaborate over high-speed and high-bandwidth networks connected to heterogeneous supercomputing resources and large data stores" [Leigh, et. al., 1997, p. 1 of 9]. In the early stages of Tele- immersion there were two main factors driving the research: the significant processing load of real-time and simulated computational steering, and the sheer bulk of the data sets being generated for scientific visual analysis [Leigh, et. al., 1997]. Now the growing number of immersive VR sites is motivating a need to support human-to-human interaction and work over wide networks of immersive virtual environments. This research focuses heavily on issues of collaborative awareness in these networked, immersive virtual environments. Collaborative awareness, in this context, is a concept that encompasses the caveats of one's knowledge about the CVE and its occupants. As a result of this study, software has been designed to provide support not only for collaborative awareness, but also for several other dimensions of collaboration. / Master of Science