System Resource Sharing for Synchronous Collaboration

We describe problems associated with accessing data resources external to the application, which we term externalities, in replicated synchronous collaborative applications (e.g., a multiuser text editor). Accessing externalities such as les, databases, network connections, environment variables and the system clock is not as straightforward in replicated collaborative software as in single-user applications and centralized collaborative systems. We describe ad hoc solutions that have been used previously. Our primary objection to the ad hoc solutions is that the developer must program dierent behavior into the dierent replicas of a multi-user application, which increases the cost and complexity of development. We introduce a novel general approach to accessing externalities uniformly in a replicated collaborative system. The approach uses a semi-replicated architecture where the actual externality resides at a single location and is accessed via replicated proxies. The proxies multiplex input to and output from the single instance of the externality. This approach facilitates the creation of replicated synchronous groupware in two ways: (1) developers use the same mechanisms as in traditional single-user applications (2) developers program all replicas to execute the same behavior. We describe a general design for proxied access to read{only, write{only and read{write externalities. We discuss the tradeos of this semi- replicated approach over full, literal replication and the class of applications to which this approach can be successfully applied. We also describe details of a prototype implementation of this approach within a replicated collaboration-transparency system, called Flexible JAMM (Java Applets Made Multi-user)

An environment for studying the impact of spatialising sonified graphs on data comprehension

We describe AudioCave, an environment for exploring the impact of spatialising sonified graphs on a set of numerical data comprehension tasks. Its design builds on findings regarding the effectiveness of sonified graphs for numerical data overview and discovery by visually impaired and blind students. We demonstrate its use as a test bed for comparing the approach of accessing a single sonified numerical datum at a time to one where multiple sonified numerical data can be accessed concurrently. Results from this experiment show that concurrent access facilitates the tackling of our set multivariate data comprehension tasks. AudioCave also demonstrates how the spatialisation of the sonified graphs provides opportunities for sharing the representation. We present two experiments investigating users solving set data comprehension tasks collaboratively by sharing the data representation

Interactive tabletops in education

Interactive tabletops are gaining increased attention from CSCL researchers. This paper analyses the relation between this technology and teaching and learning processes. At a global level, one could argue that tabletops convey a socio-constructivist flavor: they support small teams that solve problems by exploring multiple solutions. The development of tabletop applications also witnesses the growing importance of face-to-face collaboration in CSCL and acknowledges the physicality of learning. However, this global analysis is insufficient. To analyze the educational potential of tabletops in education, we present 33 points that should be taken into consideration. These points are structured on four levels: individual user-system interaction, teamwork, classroom orchestration, and socio-cultural contexts. God lies in the detail

Groupware design : principles, prototypes, and systems

Computers are valuable tools for a wide range of work tasks. A substantial limitation on their value, however, is the predominant focus on enhancing the work of individuals. This fails to account for the issues of collaboration that affect almost all work. Research into computer supported cooperative work (CSCW) aims to eliminate this deficiency, but the promise of computer systems for group work has not been met. This thesis presents four design principles that promote the development of successful groupware. The principles identify the particular problems encountered by groupware, and provide guidelines and strategies to avoid, overcome, or minimise their impact. Derived from several sources, the major influence on the principles development is an investigation into the relationship between factors affecting groupware failure. They are stimulated by observations of groupware use, and by design insights arising from the development of two groupware applications and their prototypes: Mona and TELEFREEK. Mona provides conversation-based email management. Several groupware applications allow similar functionality, but the design principles result in Mona using different mechanisms to achieve its user-support. TELEFREEK provides a platform for accessing computer-supported communication and collaboration facilities. It attends to the problems of initiating interaction, and supports an adaptable and extendible set of "social awareness" assistants. TELEFREEK offers a broader range of facilities than other groupware, and avoids the use of prohibitively high-bandwidth communication networks. TELEFREEK demonstrates that much can be achieved through current and widely accessible technology. Together, Mona and TELEFREEK forcefully demonstrate the use of the design principles, and substantiate the claim of their utility

Co-present photo sharing on mobile devices

This dissertation researches current approaches to photo sharing. We have found that most current methods of photo sharing are not as compelling as traditional photo sharing - with the increasing in popularity of digital photography, consumers do not print photos as often as before and thus typically require a group display (such as a PC) to view their photographs collectively. This dissertation describes a mobile application that attempts to support traditional photo sharing activities by allowing users to share photos with other co-present users by synchronizing the display on multiple mobile devices. Various floor control policies (software locks that determine when someone can control the displays) were implemented. The behaviour of groups of users was studied to determine how people would use this application for sharing photos and how various floor control policies affect this behaviour

Using teleporting, awareness and multiple views to improve teamwork in collaborative virtual environments

Mobile Group Dynamics (MGDs) are a suite of techniques that help people work together in large-scale collaborative virtual environments (CVEs). The present paper describes the implementation and evaluation of three additional MGDs techniques (teleporting, awareness and multiple views) which, when combined, produced a 4 times increase in the amount that participants communicated in a CVE and also significantly increased the extent to which participants communicated over extended distances in the CVE. The MGDs were evaluated using an urban planning scenario using groups of either seven (teleporting + awareness) or eight (teleporting + awareness + multiple views) participants. The study has implications for CVE designers, because it provides quantitative and qualitative data about how teleporting, awareness and multiple views improve groupwork in CVEs. Categories and Subject Descriptors (according to ACM CCS): C.2.4 [Computer-Communication Networks]: Distributed Systems – Distributed applications; H.1.2 [Models and Principles]: User/Machine Systems – Human factors; Software psychology; H.5.1 [Information Interfaces and Presentation]: Multimedia Information Systems – Artificial, augmented and virtual realities; H.5.3 [Information Interfaces and Presentation]: Group and Organization Interfaces – Collaborative computing; Computer-supported cooperative work; Synchronous interaction; I.3.7[Computer Graphics]: Three Dimensional Graphics and Realism – Virtual Realit

Interactive tabletops in education

Interactive tabletops are gaining increased attention from CSCL researchers. This paper analyses the relation between this technology and teaching and learning processes. At a global level, one could argue that tabletops convey a socio-constructivist flavor: they support small teams that solve problems by exploring multiple solutions. The development of tabletop applications also witnesses the growing importance of face-to-face collaboration in CSCL and acknowledges the physicality of learning. However, this global analysis is insufficient. To analyze the educational potential of tabletops in education, we present 33 points that should be taken into consideration. These points are structured on four levels: individual user-system interaction, teamwork, classroom orchestration, and socio-cultural contexts. God lies in the details

Using mobile group dynamics and virtual time to improve teamwork in large-scale collaborative virtual environments

Mobile group dynamics (MGDs) assist synchronous working in collaborative virtual environments (CVEs), and virtual time (VT) extends the benefits to asynchronous working. The present paper describes the implementation of MGDs (teleporting, awareness and multiple views) and VT (the utterances of 23 previous users were embedded in a CVE as conversation tags), and their evaluation using an urban planning task. Compared with previous research using the same scenario, the new MGD techniques produced substantial increases in the amount that, and distance over which, participants communicated. With VT participants chose to listen to a quarter of the conversations of their predecessors while performing the task. The embedded VT conversations led to a reduction in the rate at which participants traveled around, but an increase in live communication that took place. Taken together, the studies show how CVE interfaces can be improved for synchronous and asynchronous collaborations, and highlight possibilities for future research

Proceedings of the ECSCW'95 Workshop on the Role of Version Control in CSCW Applications

The workshop entitled "The Role of Version Control in Computer Supported Cooperative Work Applications" was held on September 10, 1995 in Stockholm, Sweden in conjunction with the ECSCW'95 conference. Version control, the ability to manage relationships between successive instances of artifacts, organize those instances into meaningful structures, and support navigation and other operations on those structures, is an important problem in CSCW applications. It has long been recognized as a critical issue for inherently cooperative tasks such as software engineering, technical documentation, and authoring. The primary challenge for versioning in these areas is to support opportunistic, open-ended design processes requiring the preservation of historical perspectives in the design process, the reuse of previous designs, and the exploitation of alternative designs. The primary goal of this workshop was to bring together a diverse group of individuals interested in examining the role of versioning in Computer Supported Cooperative Work. Participation was encouraged from members of the research community currently investigating the versioning process in CSCW as well as application designers and developers who are familiar with the real-world requirements for versioning in CSCW. Both groups were represented at the workshop resulting in an exchange of ideas and information that helped to familiarize developers with the most recent research results in the area, and to provide researchers with an updated view of the needs and challenges faced by application developers. In preparing for this workshop, the organizers were able to build upon the results of their previous one entitled "The Workshop on Versioning in Hypertext" held in conjunction with the ECHT'94 conference. The following section of this report contains a summary in which the workshop organizers report the major results of the workshop. The summary is followed by a section that contains the position papers that were accepted to the workshop. The position papers provide more detailed information describing recent research efforts of the workshop participants as well as current challenges that are being encountered in the development of CSCW applications. A list of workshop participants is provided at the end of the report. The organizers would like to thank all of the participants for their contributions which were, of course, vital to the success of the workshop. We would also like to thank the ECSCW'95 conference organizers for providing a forum in which this workshop was possible