Speed Perception: An objective measure of presence in virtual environments
Guy Wallis, Jennifer Tichon, Tony Mildred · 2007
Traditionally, there has been a relatively small cohort of industries making use of simulator technology. Improvements in fidelity, affordability and industry awareness have seen that number increase dramatically, but often without a good understanding of how best to maximize its effectiveness. In choosing a suitable platform for conducting simulator-based training, a company must consider simulator design including the range of sensory feedback, levels of interaction supported, and mobility. But which simulator type will produce the best learning outcomes? RailCorp utilize three simulators: a high-fidelity, large-screen system; an in-cab simulator; and a portable, video-based system. Previous research indicates that learning outcomes are constrained by the extent to which trainees feel immersed or ‘present’ in the simulated environment. Measurement of this variable primarily relies on subjective self-reports, longitudinal studies of safety outcomes, or physiological measures hypothesized to corroborate presence. This paper describes some preliminary work undertaken to obtain a direct, objective measure of presence and hence training efficacy. Nine expert train drivers participated in 48 trials conducted with the three simulators, during which, their ability to estimate their simulated speed was measured. Preliminary results suggest striking differences between the simulators. The large-screen and in-cab simulators produced similarly accurate results, but there was a clear tendency to underestimate speed using the large screen. Speed estimates based on video images were less accurate and actually revealed the opposite trend, i.e. a tendency to overestimate speeds. Estimates from the large-screen versus video differed significantly (p<0.05). Overall, the results indicate that the speed perception measure is sensitive to differences in a user’s simulated experience. It can, therefore, provide an objective guide to a simulator’s limitations, and help motivate future modifications.