The rest frame construct and presence hypothesis together suggest three closely related areas of research. These have to do with the measurement, manipulation and malformation of selected rest frames.
Area I. Presence reflects selected rest frame decisions. This suggests that it is possible to measure presence by creating a conflict between real and virtual rest frame cues and then evaluating the relative influence of the virtual cues on the selected rest frame. Thus, a scale for presence can be constructed in terms of the ability of a virtual environment to perceptually overwhelm conflicting real stimuli.
Area II. What stimuli influence selected rest frame decisions? This leads to the study of techniques for manipulating the selected rest frame and the sense of presence in virtual environments. In particular, the use of foreground occlusions was investigated.
Area III. What are the consequences when the appropriate selected rest frame is unclear? This produces at least two interesting subcases. Area III A. Visual cues determine the selected rest frame, despite conflicting inertial cues. As discussed in Section 3.3.2, this suggests a useful way of linking together presence and six classes of visual illusions. Area III B. No functional selected rest frame is formed at all. As a slight refinement to sensory rearrangement theory, it was suggested in Section 3.3.5 that this condition is the underlying cause of motion sickness.
A typical dissertation takes as its topic a single, often narrow, line of research and pursues it to a definitive conclusion. The present dissertation research was not conducted in that fashion, as a matter of deliberate policy. The reason is that the usefulness of the RFC lies precisely in its ability to show relationships, and to allow borrowings, between distinct areas of research. The test of a unifying formulation does not lie in one specific line of research, but rather in its ability to consistently provide useful guidance across its domain of applicability. Hence, as described below, this dissertation reports on separate lines of research in each of Areas I, II and III, as well as an experiment on the influence of cognitive factors on presence and preliminary work on the application of foreground occlusions to reducing ``luning'' (an unfortunate side-effect of certain binocular displays).