Alberto Barbosa Raposo

Applying the 3C Model to Groupware Development

This paper introduces an approach based on the 3C (communication, coordination and cooperation) collaboration model to the development of collaborative systems. The 3C model is studied by means of a detailed analysis of each of its three elements, followed by a case study of a learningware application and the methodology of a web-based course, both designed based on this model. Moreover, this paper describes a component-based system architecture following this 3C approach.

Coordination of collaborative activities: a framework for the definition of tasks interdependencies

The coordination of interdependencies between tasks in collaborative environments is a very important and difficult endeavour. The separation between tasks and interdependencies allows for the use of different coordination policies in the same collaborative environment by changing only the coordination mechanisms that control the interdependencies. This paper presents a framework for the definition of interdependencies that frequently occur in collaborative activities. By means of a clear characterization of interdependencies, it is possible to identify coordination mechanisms to manage them, opening the way toward a powerful coordination tool capable of encompassing a wide range of collaborative applications. An implementation of the coordination model of a collaborative virtual environment based on the proposed framework is given as example.

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. r 2001 Elsevier Science Ltd. All rights reserved.

Inter- and intra-relationships between communication coordination and cooperation in the scope of the 3C Collaboration Model

Based on the 3C collaboration model, this article descries the mapping of a variety of collaboration forms onto inter-relationships between communication, coordination and cooperation. In order to investigate how to provide computational support for these three functional collaboration dimensions the analysis shifts from the inter-relationships between these three dimensions to their intra-relationships. Finally, Gestalt psychology principles are used to discuss the suitability of the approach to human perception.

PAR: A Collaborative Game for Multitouch Tabletop to Support Social Interaction of Users with Autism.

Abstract We present the design and evaluation of the multiuser collaborative game PAR for multitouch tabletops. PAR was designed with four collaboration patterns to contribute to the social interaction skills of youngsters with Autism. These were obtained from collaboration patterns used in applications for users with High-Functioning Autism (HFA) and modified according to the requirements of target users (youngsters with autism more impaired than those with HFA). PAR was evaluated using research criteria about social interaction actions achieved by the users during the collaborative work in the game. We conducted 51 test sessions recorded in audio and video (17 sessions for each game phase) with 5 youngsters with Autism, changing pairs of players and their roles in the game. The results suggest that each collaboration pattern motivates the need for collaboration and encourages the creation of social interaction intentions or situations among users.

Educational technology for collaborative virtual environments

3D information systems for education must be investigated and adopted for a more involving form of learning. It is in this context that we propose the use of Second Life as an environment for collaborative learning and generation of new educational content. Second Life is a simulator of real life and relationships, an entirely three-dimensional virtual world. There, besides interacting with users from the whole world in real time, it is also possible to create ones own objects and businesses, and generate new alternatives of content, exchange of information, and learning.

Improving 3D navigation in multiscale environments using cubemap-based techniques

Navigation in virtual 3D environments, especially those with multiscale features, is still a problem for many users. In this regard, a good design of the navigation interfaces is critical to ensure that the users navigate with the best possible efficiency and comfort. In this paper, we present improvements made to two well-known interfaces: fly, including support to collision treatment and automatic navigation speed adjustment in relation to scale, and examine, with automatic pivot point. Such techniques are based on the cubemap structure. Usability tests have shown a significant improvement in the execution of navigation tasks.

Towards the use of cad models in VR applications

One of the main objectives of the engineering departments of large industries is the construction of integrated information systems to control their projects, offering resources for the 3D visualization of their models with enough realism to be used for virtual prototyping, design review, change management systems, and training, among other activities. This work analyzes the main problems related to the production of Virtual Reality (VR) models derived from CAD (Computer-Aided Design) models, which allows the user to interact with them in real-time and have an immersive sensation. The paper presents ENVIRON (ENvironment for VIRtual Objects Navigation), an application that was developed motivated by the necessity of using VR in large industrial engineering models coming from CAD tools.

ENVIRON: visualization of CAD models in a virtual reality environment

This paper presents ENVIRON (ENvironment for VIRtual Objects Navigation), an application that was developed motivated by the necessity of using Virtual Reality in large industrial engineering models coming from CAD (Computer Aided Design) tools. This work analyzes the main problems related to the production of a VR model, derived from the CAD model.

v-Glove: A 3D Virtual Touch Interface

Traditional interaction devices such as mouse and keyboard do not adapt very well to immersive environments, since they were not ergonomically designed for it. The user may be standing or in movement and these devices were projected to work on desks. Moreover, in the current interaction model for immersive environments, which is based on wands and 3D mice, a change of context is necessary every time to execute a non-immersive task. These constant context changes from immersive to 2D desktops introduce a rupture in the user interaction with the application. The objective of this work is to develop a device that maps a touch interface in a virtual reality immersive environment. In order to interact in 3D virtual reality immersive environments a wireless glove (v-Glove) was created, which has two main functionalities: tracking the position of the users index finger and vibrate the fingertip when it reaches an area mapped in the interaction space to simulate a touch feeling. Quantitative and qualitative analysis were performed with users to evaluate the v-Glove, comparing it with a gyroscopic 3D mouse.