Continuous Assessment of Presence in Stereoscopic Displays

Abstract

Presence, a sense of ‘being there’ evoked by a display, can be regarded as a concept of central importance in the evaluation of broadcasting and entertainment services in general and virtual reality applications in particular. Subjective methods of assessing presence that have either been used or proposed to date do not provide a measure of temporal variation in observers' presence. To overcome this limitation, we have applied the method of continuous assessment (ITU-R, BT 500-7) to the measurement of presence. Thirty observers (twelve at IPO, eighteen at UoE) with normal or corrected-to-normal vision and good stereo-acuity viewed a stereoscopic film. While watching, observers were asked to continuously rate their perceptions of depth, naturalness and presence. The stimulus material varied considerably in the amount and strength of the visual cues presented over time. This enabled us to investigate whether the extent of sensory information presented to an observer was a determinant of presence, as proposed by Sheridan [1992 Presence: Teleoperators and Virtual Environments1(1) 120 – 125]. The results, which were very similar across two independent laboratories, suggested that continuous assessment provides a promising methodology for the subjective assessment of temporal variation in the observer's sense of presence. Further, increasing the extent of sensory information presented to an observer may enhance the sense of presence, provided the depth cues introduced are consistent and within natural bounds. [ Note: First and second author in arbitrary order.]