This paper will examine the dangers of attempting to measure the `presence' of a VR system as a one-dimensional parameter. The question of whether presence is a valid measure of a VR system will also be addressed

When collaborating individuals rely on situation awareness (the gathering, incorporation and utilization of environmental information) to help them combine their unique knowledge and skills and achieve their goals. When collaborating across distances, situation awareness is mediated by technology. There are few guidelines to help system analysts design systems or applications that support the creation and maintenance of situation awareness for teams or groups. We propose a framework to guide design decisions to enhance computer-mediated situation awareness during scientific research collaboration. The foundation for this framework is previous research in situation awareness and virtual reality, combined with our analysis of interviews and observations of collaborating scientists. The framework suggests that situation awareness is comprised of contextual, task and process, and socio-emotional information. Research in virtual reality systems suggests control, sensory, distraction and realism attributes of technology contribute to a sense of presence (Witmer & Singer, 1998). We suggest that consideration of these attributes with respect to contextual, task and process, and socio-emotional information provides insights to guide design decisions. We used the

In this paper we present the results of a qualitative, empirical study exploring the impact of immersive technologies on presence and engagement, using the interactive drama Façade as the object of study. In this drama, players are situated in a married couple’s apartment, and interact primarily through conversation with the characters and manipulation of objects in the space. We present participants ’ experiences across three different versions of Façade – augmented reality (AR) and two desktop computing based implementations, one where players communicate using speech and the other using typed keyboard input. Through interviews and observations of players, we find that immersive AR can create an increased sense of presence, confirming generally held expectations. However, we demonstrate that increased presence does not necessarily lead to more engagement. Rather, mediation may be necessary for some players to fully engage with certain interactive media experiences. Author Keywords Virtual or augmented reality experiences, interactive drama,

We propose a synthesis of two current major approaches to understanding the effectiveness of VR systems. We propose cognitive presence as a single, unified concept of presence which includes previous ideas of presence in a cognitive psychological framework, and propose a methodology for measuring it. We then critically examine the notion of cognitive presence, as a way of conceptualizing HCI quality in virtual environments 1. CURRENT IDEAS OF PRESENCE Presence is currently the focus of much VR research. Many researchers believe that presence can be used as a general measure of VR effectiveness ([21], [10]), and that creating VR systems which increase presence in users will contribute towards better task performance on those systems ([10], [13]). Presence is currently of interest to a wide variety of researcher, ranging from those who are interested in how display technologies are related to presence (for example, [12], [17] and [1]) to those who are interested in the human interface aspects of VR (for example [10],[11], [15] and [19]).

Many presence studies show the importance of display variables in determining presence. However, very little empirical evidence exists to support the notion of “the suspension of disbelief ” or other psychological determinants of presence. We argue from a cognitive presence perspective that presence can be considered as an extension of perception, a process which is known to be significantly affected by the perceiver’s mental state. We support our argument by presenting the results of a large study (n=103) in which users were conceptually primed by reading a booklet either related to or unrelated to a VE and then were left to explore that VE with either a high quality or low quality display. We found a significant interaction effect between display quality and priming, showing that the mental state of the user sets a context which affects their experience of presence as measured using two scales. We conclude that, like perception, presence does not simply occur as a consequence of sensory input only, but that it is a constructive process in which the VE user creates an experience using both sensory and psychological inputs.

Presence is a user's subjective sensation of "being there" in a mediated environment. Its determinants include the extent of sensory information within a mediated environment, the user's ability to control their sensors and modify content within the environment, and individual-difference based factors. Although direct subjective ratings of presence have been used, the construct may be unclear to nave observers, and previous work in our laboratory has shown that ratings of presence may be biased towards different characteristics of the display. In the present study focus groups were used to: (i) establish whether viewers refer to sensations of presence, unprompted, (ii) identify viewers' descriptions of their experiences of stereoscopic TV, and (iii) identify the programme types best suited to advanced broadcast presentations. Results showed that nonexperts describe sensations of presence without prompting whilst watching stereoscopic television, relating it to involvement, realism and naturalness. In addition, there was a general consensus that live events, such as sports matches, theatre and concerts are the programme types best suited to high-presence broadcast presentations, through advanced broadcast services such as Immersive Television.

Presence in Collaborative Virtual Environments (CVEs) can be divided into personal presence and co-presence. Personal presence is having a feeling of "being there" in the CVE oneself. Co-presence is having a feeling that one is in the same place as the other participants, and that one is collaborating with real people. We investigated the effects that avatar realism and functionality (in terms of simple gestures and facial expressions) have on co-presence in a collaborative virtual environment, by means of two small group behaviour experiments with 18 participants each. We measured co-presence subjectively, using a co-presence questionnaire that we developed. We found that there was a significant difference between the co-presence scores generated by avatars of different degrees of realism in their appearance. More realistic avatars generated higher levels of co-presence. We also found that avatars having gestures and facial expressions produced a significantly higher level of co-presence when compared to static avatars. We were not able to find the correlation between presence and copresence reported in some studies.

We have designed a mobile-PDA-based- interface for real-time control of virtual characters in multiuser semi-immersive Virtual Environments-using a large rear-projection screen. The proof-of-concept implementation we present shows the potential of handheld devices as powerful interfaces to Virtual Reality applications. This technique eliminates the display of floating menus and other widgets over the simulation screen. A brief discussion on the advantages and disadvantages of using a handheld for 3D interaction is presented as well.

Virtual environments (VEs) are the most advanced human-computer interfaces yet developed. Researchers, by the development of new methods, theories, and technologies, have endeavored to make effective VEs. The definition of effectiveness changes based on the application of the VE. For flight simulators, training transfer is important. For architectural walkthroughs, accurate perception of space is important. For treatment of phobias and post-traumatic stress disorders, presence – evoking in patients the feeling that they are near the source of their phobia or stress – is important [Hodges, 1994]. It is on this last concept, presence, that this paper focuses. Rothbaum and Hodges ’ VE system for graded exposure treatment of acrophobia strives to bring patients near the source of their phobias [Hodges, 1994]. They state that “the user’s sense of presence is the defining factor in the [successful treatment of acrophobia]. ” We believe this is true for all phobia treatment systems: the system must evoke presence in order to work. Such systems are useful as they allow much of the effectiveness of in vivo exposure with the safety, convenience, and reduced cost of in-office therapy [Hodges, 1995]. To ensure the systems evoke presence in users, developers endeavor to build the best VEs possible: stereo portrayal (as opposed to mono) in the headmounted display, realistic models and lighting, low lag, high frame rate, etc.

A between-group experiment was carried out to assess whether two different presence questionnaires can distinguish between real and virtual experiences. One group of ten subjects searched for a box in a real office environment. A second group of ten subjects carried out the same task in a virtual environment that simulated the same office. Immediately after their experience, subjects were given two different presence questionnaires in randomized order: the Witmer and Singer Presence (WS), and the questionnaire developed by Slater, Usoh, and Steed (SUS). The paper argues that questionnaires should be able to pass a ‘‘reality test,’ ’ whereby under current conditions the presence scores should be higher for real experiences than for virtual ones. Nevertheless, only the SUS had a marginally higher mean score for the real compared to the virtual, and there was no significant difference at all between the WS mean scores. It is concluded that, although such questionnaires may be useful when all subjects experience the same type of environment, their utility is doubtful for the comparison of experiences across environments, such as immersive virtual compared to real, or desktop compared to immersive virtual. 1