See Section 2.2 for a review of presence. Experiment CogE1 addressed the importance of presence, by showing that (in addition to many other factors related to the quality of an interface) presence is linked to the meaningfulness of stimuli. This adds importance to the search for robust presence measures described in Chapter 4.
This research was led by Dr. Hoffman. As I was second author on this experiment, and as its role (for current purposes) is only supportive to research in Areas I, II and III, full details are deferred to a journal article, in press [41].
Title: CogE1: Cognitive Influences on Presence. Background: While presence is characteristic of virtual environments, the factors influencing it, and its consequences, remain unclear. Previous research has focused primarily on the computer side of the human-computer interface: i.e., display issues such as FOV and lag. The current experiment studied the human side of the interface. We studied the effect of meaningfulness on presence and recall. To the extent that presence can be demonstrated to be a cognitive phenomenon, it becomes more important to study, because of the higher probability that presence will be linked to such things as performance and training transfer. Hypothesis: Increasing the level of meaningfulness while other variables are held constant increases the level of presence. Higher levels of expertise may correlate with a stronger effect for meaningfulness on both presence and memory performance. Methods: Meaningfulness was manipulated by comparing master chess positions with matched random positions. Positions were shown in a Division dVisor HMD. Positions were labelled meaningful or meaningless in the virtual environment for the benefit of the non-players used as controls, and to thus match any possible demand characteristics between chess players and non-players. Four levels of chess expertise were used, ranging from those not knowing the rules of chess to strong tournament players. The ``old-new'' memory recognition task measured accuracy in reporting which positions had been seen previously. The experiment was performed double-blind, with the experimenter blind to both the hypothesis and the chess strength of particular subjects. Thirty-three unpaid adult volunteers participated. Results: Presence ratings were significantly higher for meaningful than meaningless positions for all participants except non-players. No difference in presence ratings was found between the three levels of expertise above non-players. On the old-new memory recognition task, recognition rates were significantly higher (and near-perfect) for the meaningful positions, but only for the strongest group of chess players. The meaningful/meaningless interaction with expertise was significant. Conclusions: The results show that the amount of presence felt by individuals depends on whether the contents were meaningful to them, independent of display parameters. This demonstrates that presence is related to cognitive, not simply perceptual issues. Only a small level of expertise was needed to produce a large effect of meaning on presence. The memory recall results are consistent with Chase and Simon [18], extended to a different memory task.