Abstract: In this paper, a theoretical model is proposed to account for the incorporation of critical social influence effects appropriate to the design and implementation of collaborative virtual environments. The proposed social influence threshold model provides a framework for both substantive basic and applied research, as well as a way of determining functional specifications for implementing behavioral realism within collaborative virtual environments and testing the social interactive functionality of them.

Abstract: A distributed virtual environment (DVE) is a software system that allows users on a network to interact with each other by sharing a common view of their states. As users are geographically distributed over large networks like the Internet and the number of users increases, scalability is a key aspect to consider for real-time interaction. Various solutions have been proposed to improve the scalability in DVE systems but they are either focused on only specific aspects or customized to a target application. In this paper, we classify the approaches for improving scalability of DVE into four categories: communication architecture, interest management, concurrency control, and data replication. We then propose a scalable network framework for DVEs, ATLAS. Incorporated with our various scalable schemes, ATLAS meets the scalability of a system as a whole. By providing system developers with a set of APIs as a network infrastructure, ATLAS intends to support various applications The integration experiences of ATLAS with several virtual reality systems ensures the versatility of the proposed solution.

Abstract: In this paper, we describe a collaborative navigation task in CVE. As a work in process, we present a process model of the task and design an experiment to test hypotheses generated by this process model. Using this experimental approach, we investigated the effect of the dimension of egocentric-exocentric perspectives on collaborative navigation performance. Results favor an egocentric perspective display. We also discuss the implications of this work for the design of interaction techniques to support collaborative navigation and awareness in CVE.

Abstract: If large-scale shared virtual worlds are to be established on the Internet, they must be based on technologies that allow them to adapt, scale, and evolve continuously-that is, without their being taken offline. In the course of designing NPSNET-V, an architecture intended to satisfy these criteria through component-based dynamic extensibility, the authors recognized the need for a consistent, unified component framework. This framework, which they implemented in Java™, allows one to construct applications as component hierarchies rooted at an invariant microkernel. A simple extensible interface layer and event model allow components to communicate with one another, and an XML configuration and serialization mechanism permits applications to store and transmit component and application state in a versatile standardized format. After an initial bootstrapping process, one may add, remove, and upgrade components at run time, and one may introduce newly loaded Java™ code anywhere in the application hierarchy at any time. The complications posed by this reconfigurability and the hierarchical nature of NPSNET-V applications led the authors to develop a consistent design strategy, which they based largely on several common design patterns. The most critical design pattern that they used was the Model-View-Controller pattern, which forms the basis of the NPSNET-V entity model.

Abstract: A multiscale Collaborative Virtual Environment (mCVE) is a virtual world in which multiple users can independently resize themselves to work together on different sized aspects of very large and complicated structures. Interactions among users in an mCVE differ in many ways from those in traditional collaborative virtual environments. In this paper we explore collaboration-related issues affected by multiscale, such as social presence, perception of proximity, and cross-scale information sharing. We also report results of an experiment with our mCVE prototype system, which show the impact of multiscale capabilities on social interactions.

Abstract: In this paper we describe The Pond, a system used to search for and visualise data elements on an engaging tabletop display. The Pond uses methods of unencumbered interaction and audio feedback to allow users to investigate data elements, and supports shoulder-to-shoulder collaboration with the physical Pond artefact mediating the collaboration between those people gathered around it. The user interface is based on an ecosystem metaphor, presenting data elements in the form of shoals of aquatic creatures inside a virtual 3D pond. The Pond is an interactive system offering an appealing and novel way to search for and interchange information. We describe the motivation and design choices behind The Pond, the system as it stands today, details of its implementation, and observations from a study of The Pond in use.

Abstract: The design of a Virtual Environment (VE) is a distributed problem of multi-user access to shared resources. Such problem requires careful design decisions in order to provide a seamless system infrastructure capable of supporting flexible interactions in the shared scenarios.The complexity of this domain has led to intricate software systems that provide ad-hoc solutions to specific problems. Furthermore, many of them have gone to a dead end, due to their non-extensible design and their lack of code and module reuse.This paper presents a VE that is constructed on top of a component groupware framework. Our major aim is to provide an extensible infrastructure offering a set of collaborative services in a seamless way. At the conceptual level, it provides essential collaborative services: shared sessions, support for synchronous and asynchronous components, security, coordination, and a server-side awareness infrastructure. At the architectural level, the framework is constructed on top of a middleware integration platform and uses high performance publish/subscribe notification services. Finally, we present the advantages and limitations of this approach.

Abstract: In this paper we describe an infrastructure and prototype system for sharing of visiting experiences across multiple media. The prototype supports synchronous co-visiting by physical and digital visitors, with digital access via either the World Wide Web or 3-dimensional graphics.

Abstract: One of the challenges facing developers of large-scale and content-rich Collaborative Virtual Environments is the lack of bandwidth to support the exchange of information between participants. It is usually not feasible for all participants to receive all the data produced by all other participants. It is therefore necessary to filter out some of such data for every user according to their interest. This paper presents an interest management mechanism based on each user's visibility of others. Its main features include occlusion awareness and visibility-based filtering, no need for a server and renderer-based visibility calculation.

Abstract: CVEs are computer-based worlds that can enhance and expand our ability to communicate with others and collaborate on the creation and exploration of data They are a complement to existing tools that support human-human collaboration Many computer-based tools for communication and collaboration (such as email) focus on the passage and sharing of content and assume a baton-passing, cooperative model of human-human interaction; that is, individual content creation, manipulation and editing, with asynchronous content exchange and mark-up Where synchronous communication is supported, tools tend to target the data to be shared (distributed whiteboards) or give primary focus to the human-human communication itself (chat spaces) In all cases, the presence of people along with the data is very limited (eg static images, shared telepointers) By contrast CVEs focus on putting interactive, dynamic representations of data and people into virtual landscapes and offer rich mechanisms for navigation, exploration and communicationCVEs can be graphical or textual They can be task-specific - supporting a focused set of actions over carefully rendered data sets - or can be task-independent - offering editable spaces wherein objects and data are created, modified and acted upon by their inhabitants CVEs can be entirely computer-based, or can be include elements of the physical world, forming "augmented" or "mixed-reality" spaces Thus, CVEs have been designed and developed that can support exploration, communication and collaboration between people who are physically remote but co-present in an entirely computer-generated world CVEs also exist that allow people who are physically co-present to share views of metadata, people and objects that are projected into the physical worldSince the inception of this conference series in the UK in 1996, the aim of the CVE conferences has been to inspire fruitful discussion and encourage information flow between practitioners of different disciplines This is a very exciting time for designers, developers and inhabitants of CVEs, and CVE 2002 provides the perfect opportunity for discussing new advances, challenges and opportunities The increased availability of high bandwidth networks, advances in networking research, improvements in graphics and animation, and developments in input techniques and technologies all signal an explosion in the utility and availability of CVEs Scientists, artists, sociologists, engineers and designers are exploiting these technological developments and exploring the design of novel methods of interaction with others and with data, social navigation within and between data spaces, new forms of community, and new uses of CVEs in work and recreational contexts

Abstract: Distributed, real-time virtual environment (VE) architectures have traditionally been driven by quality of service (QOS) considerations, with little or no concern paid to security issues. With recent advancements in functionality, computing power and network bandwidth it has become practical to use VEs in sensitive areas such as product development with proprietary information and visualization of classified information. Consequently, previously ignored aspects of security need to be made a primary concern at the outset of designing a VE. In this paper we explore security concerns associated with a subtype of VEs: Runtime Extensible VEs (RTEVEs). We introduce a taxonomy of security issues, derived from a case study of NPSNET-V, with the goal of using this taxonomy to guide the formulation of security policy, requirements, and architectures for RTEVEs.

Abstract: This paper describes a series of studies conducted to evaluate methods of encouraging productive dialog between young children in 2D and 3D shared narrative workspaces. These workspaces were based on the Graphic Story Writer (GSW), an interactive system that produces coherent narrative text in response to user interactions. In particular, we examine the effect of introducing "positive interdependence" between collaborators as a way of encouraging productive dialog.Three studies of user interactions with the GSW were performed. An initial study of collaborative storytelling using a 2D version of the GSW demonstrated the technical feasibility of creating a shared 2D workspace devoted to narrative construction The study also confirmed the difficulty of encouraging communication between children during synchronous learning activities at separate computers. The second study introduced an additional condition that created positive interdependence between users. Users in this condition had significantly more on-task communication than those in the other conditions. We go on to describe how we modified the 2D GSW model to support collaboration in a 3D shared workspace, and provide observations and insights gained from a usability study of the 3D GSW.

Abstract: In recent years, the combination of communication networks and computer technologies have made it possible to create a cyberspace on the Internet. Recently, several 3D shared virtual spaces and worlds have been developed in which users can share the same experience in a shared virtual environment [1][10]. The next important step is to extend these environments into a "virtual society." .To realize a virtual society, it is important to obtain a large number of users in a virtual world and evaluate various issues based on the populated world. For instance, what kind of functions (especially, social functions) and interface should be supported. For this purpose we constructed a personal agent-oriented virtual society called "PAW^2" (Personal Agent World) based on our CommunityPlace system [1][2].PAW^2 [3][4] is a 3D personal agent-oriented virtual society (Figure 1). PAW^2 has improved upon past virtual spaces based on avatar and text communication by providing autonomous personal agents that interact with users plus a social and environmental infrastructure (Figure 2). We have made several observations about the unique social phenomena in PAW^2 based on our experience operating the system. In this paper, we investigate these phenomena in detail by using non-participant observation method [7] and statistic method. According to the results of observation and statistic data, we clarify what sort of phenomenon that occurred. Then, we discuss the possibility of forming culture in a virtual society and its issues.

Abstract: Virtual education environments are gaining popularity as tools to enhance student learning. These environments are often used to allow students to experience situations that would be difficult, costly, or impossible in the physical world. North Dakota State University (NDSU) provides students with environments to enhance their understanding of geology (Planet Oit), cellular biology (Virtual Cell), retailing (DollarBay), and history (Blackwood). In order to maximize the learning potential of each individual student, an ideal environment needs to provide customized lessons to that student based on his or her individual performance. One method to address this requirement is the use of case-based reasoning which is used to monitor student performance, track progress throughout an environment, compare the student to other students in the same environment, and create customized tutor dialogs to communicate this information to the student in the form of individual tutor lessons. An example of case-based lesson building software that meets the above requirements can be observed in the current DollarBay retailing environment at NDSU.

Abstract: Complex Collaborative Virtual Environments (CVEs) are usually partitioned into a structure of discrete or nested graphical objects and spaces. The use of a structure for managing graphics and spaces allows users to perform certain actions. For example, objects can then be picked up and moved around; spaces can be separated into discrete units and individually broadcast to certain users, reducing network bandwidth requirements. However, the effects of providing particular structures on users' interaction have not been investigated. In this paper, we present an analysis of pairs of users interacting in a CVE. Our analysis highlights behaviours that are caused by the simple virtual structures it provides. We derive design issues to be considered when defining the structure of a shared virtual world.

Abstract: We present an interest management technique that organizes the shared state of a virtual environment into domains and sub-domains. To specify users' interests, we have partially adopted the general aura-nimbus model. It has been generalized beyond its original spatial use to allow users to express their interests explicitly without relying on their spatial characteristics only.

Abstract: Internet and network technologies are increasing the potential to use computers to mediate collaborations between geographically dispersed individuals. However, building such systems is complex and consequently not well understood. This paper discusses the design of an experiment to study collaborative situations arising from two people collaboratively completing jigsaw puzzles. The research contributes to a broader study being undertaken with researchers at the University of Bath towards developing a more comprehensive model collaborative situations.

Abstract: Commercial organisations that are in dispute will sometimes seek to settle their differences without resorting to legal proceedings through a process of structured and facilitated negotiation called Alternate Dispute Resolution (ADR). Traditionally ADR negotiations are conducted by co-locating the mediator, witnesses, supporting evidence and representatives of each party. This paper describes a novel experiment that has been conducted at the University of Leeds to investigate whether an augmented collaborative environment could provide a realistic alternative to co-locating individuals for ADR negotiations. The individuals that took part in the experiment included an experienced mediator and practising legal representatives. The augmented collaborative environment was based on a video conferencing system that was enhanced to enable virtual artefacts representing items of evidence to be blended directly into the video streams. This experiment sits within the framework of the Court 21 Project, that is seeking to identify how new technology can be used to improve the different aspects of the legal system [10].

Abstract: The research reported in this paper describes the development and application of a tool that aims to increase the opportunity for architects to design and collaborate within virtual worlds and enable effective and transparent information exchange.The objective was to provide a Virtual Reality (VR) tool that is capable of creating 3D shapes in a shared VR environment, thus allowing the early design and its evolution to be shared by professional and client body. The system has been implemented using Java™ and Java3D™ and it has been tested on PCs workstations as well as an Sgi system running a Reality Centre.

Abstract: We developed a mixed-reality space named VILLA in order to support communications for group activities. VILLA is realized as a web home page. Locations of group members in the real world are reflected in its layout as face icons that suggest activities of people in the real world. The VILLA system provides voice chat capabilities using Internet. Since 1996 several versions were developed and operated. Based on operational experiences, we present VILLA usage examples, function evaluation, and side effects.

Abstract: Today's technology and advances in networking and telecommunications stimulate a change in the way everyday business is carried out, making it a globally distributed process, in which communication and collaboration of geographically dispersed groups is of vital importance Virtual Environments are adapting accordingly, by providing not only a better man-machine interface, but also by facilitating human-to-human interaction and collaboration over distance Therefore; new challenges are introduced in terms of distribution and interaction in Virtual Environments It is not only a question of solving the technical problems of gathering and transmitting multimedia data streams with sufficient quality and speed, but also a question of addressing the specific needs of human communication and collaboration The vision of Collaborative Virtual Environments (CVE) is to provide distributed, collaborative teams with a virtual space where they can meet as if face-to-face, co-exist and collaborate while sharing and manipulating in real-time the virtual data of interest The objective of this thesis is to provide the Virtual Environments research community with a thorough investigation of distributed, collaborative interaction between geographically dispersed teams using projection based Collaborative Virtual Environments

Abstract: For years, the research community has tried to convince sponsors of the viability of CVE applications. In that same time, the computer gaming community has rolled out hundreds of "killer apps" each year - graphical, networked, social environments.Paying a handful of students to test one's research systems certainly has its charm. Regardless, researchers at the Naval Postgraduate School set out to learn if the computer games community might be leveraged in CVE research. The first such attempt, the Army Game Project, has thus far elicited millions of dollars of funding, hundreds of thousands of test subjects, dozens of television interviews, and zero refereed publications.This talk will present my experiences as a researcher masquerading as a game developer - and as a game developer pretending to be researcher. The evening will conclude with reckless predictions for the future of Collaborative Virtual Environments.

Abstract: Virtual reality technology is increasingly being applied to globally distributed teams engaged in collaborative product design. Observations of product design teams have suggested at least four distinct modes of collaboration-complementary, competitive, peer-to-peer, and leader-follower. Another insight from observation is that collaboration consists of fluid transitions between these modes in the accomplishment completion of the design task, driven by a flexible process of subgrouping and regrouping which reflects the structure and progress of the task. Yet most collaborative virtual environment systems support only one mode of collaboration-peer-to-peer-and those that do explicitly support multiple modes (or even individual roles) do not allow fluid transitions between them in the context of the same task. In addition, no explicit support is provided to allow subgroups to be formed and dissolved. To address this problem, a collaborative virtual environment (CVE) for product design that supports multiple collaboration modes and fluid transitions is proposed; two metaphors for collaborative product design (collaboration tree and infinitely recursive conference room) are introduced; the use of a collaboration tree interface widget is detailed; and the Simple Shared Virtual Environment (SSVE) toolkit for collaborative virtual environments is described.

Abstract: Existing groupware toolkits are always built atop a programming language or system with some enhancements or extensions to support the development of a certain category of cooperative applications. This approach restricts the areas where the toolkits could be used. We argue that an ideal toolkit should be adaptive to different cooperation modes, a wide range of applications, and different programming languages. We present a groupware toolkit for replicated applications that meets these requirements by building it from a data management point of view. The architecture and certain important runtime supports are briefly explained.

Abstract: Fine-grained networks and wearable computers make it possible for the classical power of the Internet to be applied on a minute-by-minute basis in the details of our everyday life. As result, function and identity become marvelously labile. At the same time, every dark aspect of computer security has direct manifestation in the real world.

Abstract: Presence and Instant Messa in (PIM) applications are a very popular - if not the most popular - type of Collaborative Virtual Environment (CVE). Current presence technology in PIM applications can only answer people-oriented presence queries such as "Who is online?", hich may not suffice for use of PIM applications in the orkplace. In this poster, we explore more sophisticated, place-based presence systems that can also answer place-oriented presence queries, such as "Who is near?".

Abstract: In this panel we explore both the quality and effectiveness of interactions in virtual environments, and the perceived immersion in 3D collaborative virtual environments (CVEs) for work, entertainment, and collaborative learning.

Abstract: Staging public performances can be a fruitful approach to CVE research. We describe four experiences: Out of This World, a gameshow; Avatar Farm, a participatory drama; Desert Rain, a mixed reality performance; and Can You See Me Now?, a game that mixed on-line players with players on the streets. For each, we describe how a combination of ethnography, audience feedback and analysis of system logs led to new design insights, especially in the areas of orchestration and making activity available to viewers. We propose enhancing this approach with new tools for manipulating, analysing and sharing 3D recordings of CVEs.