PRESENCE IN VIRTUAL CAVE Investigating presence in VR-CAVE environment for historical sites

Using Virtual Reality (VR) to visualize sites and places from the past, present and future is widely acknowledged. This study is making use of a recently installed U-Cave VR Theatre at Birzeit University (BZU) in Palestine. This study test hypotheses connected to presence in VR environments, using the case of historical sites. Historical sites in general are important for reasons of cultural identification and environmental integrity. In many historical sites, it is difficult for a layperson to read and understand the meaning of the site, since the remaining ruins don’t provide enough information. This study contributes to improving the public understanding for historical sites by unfolding the role of VR to overcome the harsh reality of many damaged historical sites. Presence in VR environments is usually defined as “being there”, with high consideration for the physical ether of the virtual environment, it confines attention to the awareness of place. The study argues that VR technology doesn’t only provide a stereoscopic experience to subjects, it also adds a fourth dimension “time” by conveying the unconsciousness of man from the meanwhile moment to a different timeframe. This is made possible by innovative design of the VR environment and the nature of the content. It is concluded that; perceived presence is higher in a VR-CAVE environment in comparison to a 2-D traditional presentation. The results indicated that VR visualizations have a positive impact on raising the awareness of the identity of historical sites. The analysis 272 N. SHARKASI, R. HASSAN AND C. M. HAGERHALL also revealed evidence of the power of VR technology to function as a ‘time machine’ that is capable to allow users live experiences in a different time-frame. 1. Definition of Presence in Virtual Reality Environments One of the most common definitions of presence is the “subjective experience of being in one place or environment, even when one is physically situated in another” by Witmer & Singer (1998, p.225). Lombard and Ditton (1997) defined presence as the perceptual illusion of nonmediation (Lombard & Ditton, 1997), this says that the subject experiences presence, when he/she fails to recognize the mediated technology that delivers the virtual environment. Slater and Wilbur (1997) defines immersion as an objective description of aspects of the system such as field of view and display resolution while presence as a subjective phenomenon such as the sensation of being in a virtual environment (Slater & Wilbur, 1997). On the other hand, Welch (1999, p.547) stated, “there is a pervasive belief that presence is causally related to performance . despite the popularity of this notion, however, there is no solid evidence to support it” (Welch, 1999). This argument puts emphasis on presence as a subjective sensation, thus, it has been argued that subjective report is the essential basic measurement (Sheridan, 1992). A cognitive presence theory that attempts to explain human sensory perception of presence throughout an experience is expected to give rise to the design of innovative systems that offer “richer” experiences. Ijsselsteijin and Riva (2003) stated in their book Being There that “as a user experience, the feeling of ‘being there’, or presence, is not intrinsically bound to any specific type of technologyit is a product of the mind” (Ijsselsteijn & Riva, 2003, p.5). 2. Measuring Presence in VR Environments Presence is measured by subjective and objective measures. Subjective measures of presence are measures where the participant is asked for a conscious judgment, either online or post-test, of his/her psychological state/response in relation to the mediated environment (IJsselsteijn, Ridder, Freeman, Avons, & Bouwhuis, 2001). Questionnaires are commonly used as subjective measures of presence; they are more used than objective measures; because objective measures are concerned with the actual performance of the technology to deliver the sensation of the virtual experience. The VR experience, on the other hand, differs across different VR environments according to the nature of display technologies used to PRESENCE IN VIRTUAL CAVE 273 mediate the experience. Hence objective measures do not describe the experience of the user in the virtual environment and so they should always be investigated in conjunction with subjective measures. Subjective measures are based on the theory proposed to define the factors that affect presence. Vince (2004), states in his book Introduction to Virtual Reality that “the objective of VR is not to replicate our experience of the real world, but to make things as realistic and useful as possible, then solutions are within our grasp” (Vince, 2004, p.67). The assumption held in most studies about presence in virtual environment is that, human beings sense the highest level of presence in the real world (Flach & Holden, 1998; Witmer & Singer, 1998; Zahoric & Jenison, 1998; Schuemie & Van Der Mast; 1999; Slater, 2009).