FURTHER MUSINGS ON THE PSYCHOPHYSICS OF PRESENCE

This is an extension of an earlier paper (Sheridan, 1992) that conside red alternative meanings and significance of ''presence,'' the experie nce of ''being there,'' commonly called ''telepresence'' in the case o f remote control or teleoperation, and called ''virtual presence'' in the case of computer-generated simulation. In both cases presence can include feedback to the human senses of vision, hearing, and haptics, both kinesthetic and cutaneous. Presence is discussed here in terms of alternative subjective meanings, operational measurements, and meanin gful experimental comparisons. Three practical approaches to measureme nt of presence are compared, including elicitation of ''natural'' neur omuscular or vocal responses, single or multidimensional subjective sc aling, and ability to discriminate the real and immediate environment from that which is recorded/transmitted or synthesized. A new proposal , fitting into the third category, is to measure presence according to the amount of noise required to degrade the real and virtual stimulat ion until the perceived environments are indiscriminable. The author a lso opines on the stimulus magnitude, space, and time attributes of hu man interactions with a tele- or virtual environment.