Avatar gender and personal space invasion anxiety level in desktop collaborative virtual environments

We report an investigation exploring the effect of avatar gender on the anxiety level caused by personal space (PS) invasion in desktop collaborative virtual environments (DCVE). We outline an experiment in which participants, of both genders, whose avatars PS were invaded by other avatars of either gender, reported their anxiety levels through the use of a post-experiment questionnaire. The data from the questionnaire are analysed and discussed. The results suggest that the combination of the gender of the invading avatar and the avatar being invaded has an influence on the PS invasion anxiety level and that the ranking of gender combination groups has a striking difference from those observed for PS invasion in physical environments. Results also show that the participants in general did not register high anxiety, contrary to what one might expect from personal space invasion in the physical world.

Coordination components for collaborative virtual environments

This paper deals with the behavior of virtual environments from the collaboration point-of-view, in which actors (human or virtual beings) interact and collaborate by means of interdependent tasks. In this sense, actors may realize tasks that are dependent on tasks performed by other actors, while the interdependencies between tasks (through resource management and temporal relations) delineate the overall behavior of a virtual environment. Our main goal is to propose an approach for the coordination of those behaviors. Initially a generic study of possible interdependencies between collaborative tasks is presented, followed by the formal modeling (using Petri Nets) of coordination mechanisms for those dependencies. In order to implement such mechanisms, an architecture of reusable and pluggable coordination components is also introduced. These components are used in an implementation of a multi-user videogame. The presented approach is a concrete step to create virtual societies of actors that collaborate to reach common goals without the risk of getting involved in conflicting or repetitive tasks.     

Dynamic execution planning for reliable collaborative business processes

Collaborative business processes, implemented and carried out via web services and enabling dynamic interaction among organizations, are becoming more indispensable to competitiveness in the global market. As dynamic collaboration prevails, the quality of service (QoS) of collaborative processes becomes more important. A critical requirement in cases where processes involve long-term activities is to guarantee successful completion within time constraints. In this study, we developed a methodology for dynamic planning of web service execution that imparts reliability to collaborative business processes. In order to ensure that processes successfully execute within time constraints and at minimum cost, the proposed method dynamically modifies execution plans at run-time by means of fault-tolerance techniques. Since generation of an execution plan of minimum cost while guaranteeing successful completion is classified as an NP-hard problem, a heuristic algorithm was developed. Additionally, to compare the proposed algorithm’s performance with those of the branch-and-bound method and the genetic algorithm (GA), a set of experiments was conducted.     

Students’ experiences with collaborative learning in asynchronous Computer-Supported Collaborative Learning environments

This paper describes an explorative study carried out to gain response from distance students on their experiences with collaborative learning in asynchronous computer supported collaborative learning (CSCL) environments. In addition, this study also attempts to have a good grip of crucial aspects concerning collaborative learning. The study was undertaken among distance learners from the Open University of the Netherlands who were working in groups of 4–11 persons. During and after the course students’ experiences with collaborative learning were measured and after the course also students’ satisfaction with collaborative learning was assessed. The finding revealed that distance learners appreciate the opportunities to work collaboratively. They show positive experiences and are quite satisfied with collaborative learning. This study also sought to explore individuals as well as course characteristics that influenced aspects of collaborative learning, and to search aspects of collaborative learning that influenced students’ satisfaction. The findings suggested that a group product influences group process regulation and group cohesion influences students’ satisfaction with collaborative learning.     

Mediating the expression of emotion in educational collaborative virtual environments: an experimental study

The use of avatars with emotionally expressive faces is potentially highly beneficial to communication in collaborative virtual environments (CVEs), especially when used in a distance learning context. However, little is known about how, or indeed whether, emotions can effectively be transmitted through the medium of a CVE. Given this, an avatar head model with limited but human-like expressive abilities was built, designed to enrich CVE communication. Based on the facial action coding system (FACS), the head was designed to express, in a readily recognisable manner, the six universal emotions. An experiment was conducted to investigate the efficacy of the model. Results indicate that the approach of applying the FACS model to virtual face representations is not guaranteed to work for all expressions of a particular emotion category. However, given appropriate use of the model, emotions can effectively be visualised with a limited number of facial features. A set of exemplar facial expressions is presented.     

Design and implementation of a public key-based group collaboration system

We present PubKey-Wiki, a public key-based wiki group collaboration system. PubKey-Wiki allows users to authenticate themselves using public-key cryptography and gain authorizations using digital certificates. By using public key-based user authentication, users’ passwords are not sent across the network and are not stored on the web server’s host machine. Using digital certificates to authorize users to access protected files facilitates delegation of authority and simpler access control list (ACL) management, and allows the ability of a user to pass authorizations onto other users without needing to connect to the wiki’s server. The paper introduces a new approach to revocation in which revocation of certificates and revocation of public keys are handled separately and take effect immediately.The paper also introduces an algorithm, CertClosure, that computes the transitive closure of a set of certificates that contain authorization information. When a user adds or removes a certificate from his certificate directory in PubKey-Wiki, PubKey-Wiki uses the CertClosure algorithm to derive authorization rules. PubKey-Wiki stores these authorization rules in a lookup table where they can be easily referenced. When a user tries to access a protected file, PubKey-Wiki looks up and uses the relevant authorization rules to efficiently make an access control decision.     

Evaluating the effects of frame of reference on spatial collaboration using desktop collaborative virtual environments

Spatial collaboration is an everyday activity in which people work together to solve a spatial problem. For example, a group of people will often arrange furniture together or exchange directions with one another. Collaborative virtual environments using desktop PCs are particularly useful for spatial activities when the participants are distributed. This work investigates ways to enhance distributed, collaborative spatial activities. This paper explores how different frames of reference affect spatial collaboration. Specifically, it reports on an experiment that examines different combinations of exocentric and egocentric frames of reference with two users. Tasks involve manipulating an object, where one participant knows the objective (director) and the other performs the interactions (actor). It discusses the advantages and disadvantages of the different combinations for a spatial collaboration task. Findings from this study demonstrate that frames of reference affect collaboration in a variety of ways and simple exocentric-egocentric combinations do not always provide the most usable solution.     

Exploring young students' talk in iPad-supported collaborative learning environments

In the few years since its release, Apple's iPad has generated much discussion about its potential to support student learning at all levels of the education system. Much of this has focused on its physical and technical attributes, such as portability, touch-display, connectivity, and large array of apps. However, a few studies have begun to explore possible advantages of iPads being used as public work spaces, enabling students to interact more collaboratively when creating learning outputs. These studies point to other affordances such as the iPad's ability to lay flat on a desk or be propped at a convenient angle, its wide viewing range and multi-user accessible interface, as being particularly relevant in supporting collaboration.Between June and November 2013, researchers from the University of Waikato used a specifically developed ‘observeware’ app to capture display and audio data while young students (5 year olds) were using iPads in pairs for developing numeracy, literacy and problem-solving/decision-making skills. The study used Mercer's (1994) talk types framework to explore the nature of talk students engaged in while they were using the iPads and interacting with each other and their teacher, and also how features of the device may have influenced this.Results indicated exceptionally high levels of on-task talk, but that this was mostly of an affirming and non-critical nature and unsupportive of outcome improvement or refinement. While the iPad offered unique potential as a shared, public learning device, the pedagogical role of the teacher in realising this by helping students learn appropriate ‘ground rules’ to raise talk quality, was critical. This article details the methodology used and the results of the study. It discusses the important role teachers play in helping young students build oral-interaction strategies to capitalise on high levels of learning engagement, and the unique features of these devices.     

Physical and social presence in collaborative virtual environments: Exploring age and gender differences with respect to empathy

Collaborative virtual environments (CVEs) hold the immense potential of enhancing social inclusion and social support not only in younger but especially also in older people. However, there is still considerably little knowledge about the experiences of elderly when using CVEs. Additionally, there is reason to assume that men and women regardless of their age might also differ in their perceptions of CVEs, with this difference very likely being mediated by empathic abilities. Consequently, the main objective of the current study was to evaluate gender specific experiences of social and physical presence in a group of older (N = 62) and younger adults (N = 62) with respect to possible mediating influences of empathy. Results indicate no differences in physical and social presence between the two age groups, yet they support past findings that men experience more spatial presence, involvement and a higher sense of being there than women. Also, the empathy scale Fantasy considerably mediated gender differences in spatial presence, thus strengthening the theoretical assumption of a relationship between presence and empathy. Implications and future directions of these findings are discussed in detail.     

Intelligent assistance for teachers in collaborative e-learning environments

Collaborative learning environments provide a set of tools for students acting in groups to interact and accomplish an assigned task. In this kind of systems, students are free to express and communicate with each other, which usually lead to collaboration and communication problems that may require the intervention of a teacher. In this article, we introduce an intelligent agent approach to assist teachers through monitoring participations made by students within a collaborative distance learning environment, detecting conflictive situations in which a teacher’s intervention may be necessary. High precision rates achieved on conflict detection scenarios suggest great potential for the application of the proposed rule-based approach for providing personalized assistance to teachers during the development of group works.     

Challenges and opportunities in collaborative business process management: Overview of recent advances and introduction to the special issue

Modern business process management expands to cover the partner organisations’ business processes across organisational boundaries, and thereby supports organisations to coordinate the flow of information among organisations and link their business processes. With collaborative business processes, organisations can create dynamic and flexible collaborations to synergically adapt to the changing conditions, and stay competitive in the global market. Due to its significant potential and value, collaborative business processes are now turning to be an important issue of contemporary business process management, and attracts lots of attention and efforts from both academic and industry sides. In this paper, we review the development of B2B collaboration and collaborative business processes, provide an overview of related issues in managing collaborative business processes, and discuss some emerging technologies and their relationships to collaborative business processes. Finally, we introduce the papers that are published in this special issue.

Practical access control management for distributed collaborative editors

The project summarized in this article aims at developing techniques to support access control in Real-Time Distributed Collaborative Editors (RCE). The ever-increasing role of RCE in academic, industry and society comforts the expansion of data sharing and raises growing concerns about controlling access to this data. Indeed, RCE allow for a human–computer–human interaction in a decentralized fashion. Thus, access control for RCE requires a careful design since they need dynamic access changes and low latency access to shared document while maintaining its consistency.In this article, we propose a flexible access control model where the shared document and its authorization policy are replicated in the local memory of each user. To deal with latency and dynamic access changes, we use an optimistic access control technique in such a way that enforcement of authorizations is retroactive. Our model is generic enough to be deployed on the top of the most of existing logging-based collaborative systems. Indeed, it does not entail overheads and it does not affect the convergence of the shared document. We show that naive coordination between updates of both copies can create security holes on the shared document, by permitting illegal modifications or rejecting legal modifications and present our solutions to avoid these problems. Finally, we present a prototype for managing authorizations in collaborative editing work in a decentralized fashion. Thus our model may be deployed easily on mobile devices over P2P networks.     

Distributed process execution in collaborative networks

Processes are a central entity in enterprise collaboration. Collaborative processes need to be executed and coordinated in a distributed computational platform where computers are connected through heterogeneous networks and systems. Life cycle management of such collaborative processes requires a framework able to handle their diversity based on different computational and communication requirements. This paper proposes a rational for such framework, points out key requirements and proposes a strategy for a supporting technological infrastructure. Beyond the portability of collaborative process definitions among different technological bindings, a framework to handle different life cycle phases of those definitions is presented and discussed.     

协作环境中基于场所的访问控制模型

授权模型是协作环境中不可缺少的关键部件,为协作系统提供合适的授权机制很具挑战性.直接应用于协作系统的传统访问控制模型对多用户之间的协作支持不够,一些协作相关的访问控制必须在应用层上实现;针对特定协作应用背景的访问控制模型,仅适用于特定应用背景的协作系统,不能满足协作环境中更广泛的安全性需求;而现有的协作环境中通用的访问控制模型授权约束比较单一,不能满足协作环境中对授权的灵活性要求.针对这些问题,以Locale-BAC模型为基础提出协作环境中基于场所的访问控制模型,对角色、权限、场所等主要模型部件进行重新定义,实现全局访问控制和协作小组内部自主访问控制相结合的灵活的分层授权机制.     

Virtual interpersonal touch: Haptic interaction and copresence in collaborative virtual environments

As digital communication becomes more commonplace and sensory rich, understanding the manner in which people interact with one another is crucial. In the current study, we examined the manners in which people touch digital representations of people, and compared those behaviors to the manner in which they touch digital representations of nonhuman objects. Results demonstrated that people used less force when touching people than other nonhuman objects, and that people touched the face with less force than the torso area. Finally, male digital representations were touched with more force than female representations by subjects of both genders. We discuss the implications of these data to the development of haptic communication systems as well as for a methodology of measuring the amount of copresence in virtual environments.

Analyzing place metaphors in 3D educational collaborative virtual environments

In the recent years, the usage of three dimensional (3D) collaborative virtual environments (CVEs) for educational purposes has increased. The metaphors behind the design of virtual places are quite diverse, from replication of real universities to art museums and scientific labs. This paper reports the results of a case study where the students of our university, as a part of their course assignment, analyzed place metaphors used in a range of 3D educational CVEs vs. the corresponding educational goals. The students suggested a design for a virtual campus representing the Norwegian University of Science and Technology (NTNU). The results of this study provide some suggestions concerning the characterization of different design features in educational CVEs and the suitability of such features for different educational goals. Also, a preliminary set of design guidelines for an ideal virtual campus representing a real university is presented. Finally, some challenges associated with using 3D CVEs in various educational situations are discussed.     

Maintaining constraints of UML models in distributed collaborative environments

Constraint maintenance plays an important role in keeping the integrity and validity of UML models in embedded software design. While constraint maintenance capabilities are reasonably adequate in existing UML modeling applications, little work has been done to address the distributed constraint maintenance issue in multi-user collaborative modeling environments. The nature of the issue is to maintain constraint consistently across distributed sites in a collaborative modeling environment in the face of concurrency. In this paper, we propose a novel solution to this issue, which can retain the effects of all concurrent modeling operations even though they may cause constraint violations. We further contribute a distributed constraint maintenance framework in which the solution is encapsulated as a generic engine that can be mounted in a variety of single-user UML modeling applications to support collaborative UML modeling and distributed constraint maintenance in embedded software design processes. This framework has been implemented in a prototype distributed collaborative UML modeling application CoRSA.     

Collaborative virtual learning environments: design and evaluation

E-learning systems have gone through a radical change from the initial text-based environments to more stimulating multimedia systems. Such systems are Collaborative Virtual Environments, which could be used in order to support collaborative e-learning scenarios. The main aim of this paper is to aid educational designers in selecting, designing and evaluating three dimensional collaborative virtual environments in order to gain the pedagogical benefits of Computer Supported Collaborative Learning. Therefore, this paper initially discusses the potential of three dimensional networked virtual environments for supporting collaborative learning. Furthermore, based on a two-step platform selection process this paper (a) presents and compares three dimensional multi-user virtual environments for supporting collaborative learning and (b) validates the most promising solution against a set of design principles for educational virtual environments. According to these principles, an educational environment has been implemented on top of the selected platform in order to support collaborative e-learning scenarios. The design of this environment is also presented. In addition, this paper presents the results of three small scale studies carried out in a tertiary education department, to assess the educational environment. This environment has been evaluated based on a hybrid evaluation methodology for uncovering usability problems, collecting further requirements for additional functionality to support collaborative virtual learning environments, and determining the appropriateness of different kinds of learning scenarios.

Carpeno: interfacing remote collaborative virtual environments with table-top interaction

Creativity is enhanced by communication and collaboration. Thus, the increasing number of distributed creative tasks requires better support from computer-mediated communication and collaborative tools. In this paper we introduce “Carpeno”, a new system for facilitating intuitive face-to-face and remote collaboration on creative tasks. Normally the most popular and efficient way for people to collaborate is face-to-face, sitting around a table. Computer augmented surface environments, in particular interactive table-top environments, are increasingly used to support face-to-face meetings. They help co-located teams to develop new ideas by facilitating the presentation, manipulation, and exchange of shared digital documents displayed on the table-top surface. Users can see each other at the same time as the information they are talking about. In this way the task space and communication space can be brought together in a more natural and intuitive way. The discussion of digital content is redirected from a computer screen, back to a table where people can gather around. In contrast, collaborative virtual environments (CVE) are used to support remote collaboration. They frequently create familiar discussion scenarios for remote interlocutors by utilizing room metaphors. Here, virtual avatars and table metaphors are used, where the participants can get together and communicate with each other in a way that allows behaviour that is as close to face-to-face collaboration as possible. The Carpeno system described here combines table-top interaction with a CVE to support intuitive face-to-face and remote collaboration. This allows for simultaneous co-located and remote collaboration around a common, interactive table.