videoconferencing, collaboration, user behavior In this report we discuss the findings of a Web-based questionnaire aimed at discovering both patterns of use of videoconferencing systems within HP and the reasons people give for either not using, or for using such systems. The primary motivation was to understand these issues for the purpose of designing new kinds of technology to support remote work rather than as an investigation into HP's internal processes. The questionnaire, filled out via the Web by 4532 people across HP, showed that most participants (68%) had not taken part in a videoconference within the last 3 years, and only 3 % of the sample were frequent users. Of those who had used videoconference systems, the main benefits were perceived to be the ability to: see people they had never met before, see facial expressions and gestures, and follow conversations with multiple participants more easily. The main problems that users of videoconference technology perceived were: the high overhead of setting up and planning videoconferencing meetings, a lack of a widespread base of users, the perception that videoconference technology did not add value over existing communication tools, and quality and reliability issues. Non-users indicated that the main barriers were lack of access to videoconference facilities and tools and a perception that they did not need to use this tool because other tools were satisfactory. The findings from this study in a real work setting are related to findings in the

Cooperation between multiple users in a virtual environment (VE) can take place at one of three levels, but it is only at the highest level that users can simultaneously interact with the same object. This paper describes a study in a straightforward realworld task (maneuvering a large object through a restricted space) was used to investigate object manipulation by pairs of participants in a VE, and focuses on the verbal communication that took place. This communication was analyzed using both categorizing and conversation analysis techniques. Of particular note was the sheer volume of communication that took place. One third of this was instructions from one participant to another of the locomotion and manipulation movements that they should make. Another quarter was general communication that was not directly related to performance of the experimental task, and often involved explicit statements of participants' actions or requests for clarification about what was happening. Further research is required to determine the extent to which haptic and auditory feedback reduce the need for inter-participant communication in collaborative tasks.

Future teleconferencing may enhance communication between remote people by supporting non-verbal communication within an unconstrained space where people can move around and share the manipulation of artefacts. By linking walk-in displays with a Collaborative Virtual Environment (CVE) platform we are able to physically situate a distributed team in a spatially organised social and information context. We have found this to demonstrate unprecedented naturalness in the use of space and body during non-verbal communication and interaction with objects. However, relatively little is known about how people interact through this technology, especially while sharing the manipulation of objects. We observed people engaged in such a task while geographically separated across national boundaries. Our analysis is organised into collaborative scenarios, that each requires a distinct balance of social human communication with consistent shared manipulation of objects. Observational results suggest that walk-in displays do not suffer from some of the important drawbacks of other displays. Previous trials have shown that supporting natural non-verbal communication, along with responsive and consistent shared object manipulation, is hard to achieve. To better understand this problem, we take a close look at how the scenario impacts on the characteristics of event traffic. We conclude by suggesting how various strategies might reduce the consistency problem for particular scenarios.

We are interested in whether humans create a model of their partner when they jointly manipulate an object in a virtual task without haptic feedback. In such a scenario the partner is perceived as a disturbance because she/he is responsible for inconsistencies between the visual and proprioceptive feedback of the individual. To gain basic knowledge on the predictability of such disturbances we compare a pre-recorded human partner with predictable (time delay) and unpredictable (random) disturbances and two additional control conditions in a pursuit tracking task. Results indicate that the influence of the pre-recorded partner is partly predictable, therefore we assume that a model of the partner’s behavior is built by the human. 1

In this paper we introduce a new 3D interaction technique called “3-Hand Manipulation”, for multi-user collaborative manipulation of 3D objects. The 3-Hand Manipulation relies on the use of three manipulation points that can be used simultaneously by three different “hands ” of two or three users. Interestingly, the three translation motions of the manipulation points can fully determine the resulting 6 degrees of freedom motion of the manipulated object. We describe the implementation of the 3-Hand Manipulation, its graphical representations and an illustration of its use by two or three users on an insertion task in immersive virtual environment. This technique could be used in various applications of collaborative VR such as for virtual prototyping, training simulations, assembly and maintenance simulations. Categories and Subject Descriptors (according to ACM CCS): H.5.1 [Information Interfaces and Presentation (e.g. HCI)]: Multimedia Information Systems—Artificial, augmented, and virtual realities; I.3.6 [Computer Graphics]: Methodology and Techniques—Interaction techniques

The three main navigation paradigms for virtual worlds, i.e., free navigation, automatic tours, and multiuser navigation show important limitations when dealing with guided visits that involve interactive cooperation among several users in 3D virtual worlds over the Internet. In this paper, we present our research into this issue and some important results. We propose a new navigation paradigm denominated guided visit through a virtual world, where the capacity of a user guiding several remote users through the virtual world is enriched with the capacity to dynamically interchange the role of guiding between the connected users. The user that acts as a guide moves freely through the virtual world, and his/her movements are reproduced by the browsers of the other guided users. We also present the architecture and the system we developed that implements this paradigm, as well as its integration in a working realworld application that demonstrates its use. 1.

An experimental comparison of interaction in the real world and a CAVE virtual environment was carried out, varying interaction with and without virtual hands and comparing two manipulation tasks. The double-handed task was possible in the real world but nearly impossible in the VE, leading to changed behaviour. The single-handed task showed more errors in the VE but few behaviour differences. Users encountered more errors in the CAVE condition without the virtual hand than with it, and few errors in the real world. Visual feedback caused many usability problems in both tasks. The implications for VE usability and virtual prototyping are discussed.

The presented study estimates the impact of inconsistency in proprioceptive and visual feedback which can be a side effect of interaction in shared virtual environment. An important factor for interaction in virtual reality is the perception of a partner’s input as communication, not as disturbance. Therefore, the effects of disturbances correlated with a partner’s pre-recorded input are contrasted to several conditions of more or less predictable perturbations. As generalizable scenario a tracking task is used. The root mean square error and the percentage of correct performance in time are analyzed in a multivariate analysis of variance. Results indicate that people adapt to a partner’s input in timing patterns even though they ignore the magnitude of the disturbance. This indicates that the perception of Co-Presence is more depending on time factors as well.

Participants using immersive projection technology (IPT) systems tend to behave as if they were really in the space depicted by the displays. This behavioral presence leads them to adopt responses and strategies to events and situations that are similar to what they would adopt in analogous real-world situations. In this paper we discuss what happens when IPT systems are used for tele-collaboration, and each participant sees a virtual environment (VE) that includes representation of another (an avatar). In these situations we see the participants respond to that avatar as if it were the other person. We analyze several recent experiments using IPTs where participants represented to each other using avatars complete tasks together. On one hand, because these are IPT systems, a participant can not see their own avatar, and doesn't know what, if any, of their appearance and behavior is conveyed. On the other hand, they can see the appearance and behaviors of other participants ’ avatars. We explore participants ' awareness of each other through their avatars, and we demonstrate how participants successfully and unsuccessfully use their own avatar to communicate. We then analyze some of the more complex collaborative situations that are being supported in current applications and show what requirements there are for future research on avatar representations and interaction. 1

In this paper we introduce the concept of a Reconfigurable Tangible Device for manipulation of 3D objects in virtual environments by single or multiple users. This Reconfigurable Tangible Device (RTD) provides points of manipulation rigidly linked together. The shape of the RTD can be reconfigured at any time as its arms can be compressed or stretched by users at will. Due to its simple shape the Reconfigurable Tangible Device can be attached to any 3D virtual object. Then, it can fully define the motion of the virtual object in 6 Degrees of Freedom. Two examples of Reconfigurable Tangible Device were developed: one with three points of manipulation (a reconfigurable triangle) and one with four points. We illustrate how these two simple devices can match many different shapes of 3D objects, and in different contexts. Preliminary testing was conducted with the RTD based on three points of manipulation involving a collaborative manipulation task in virtual reality. It produced better subjective appreciation for the RTD compared to more classical 3D collaborative techniques.