Catálogo de publicaciones - libros

More than we realize it, knowledge is often constructed through interactions among people in small groups. The Internet, by allowing people to communicate globally in limitless combinations, has opened enormous opportunities for the creation of knowledge and understanding. A major barrier today is the poverty of adequate groupware. To design more powerful software that can facilitate the building of collaborative knowledge, we need to better understand the nature of group cognition—the processes whereby ideas are developed by small groups. We need to analyze interaction at both the individual and the group unit of analysis in order to understand the variety of processes that groupware should be supporting. This paper will look closely at an empirical example of knowledge being constructed by a small group and suggest implications for groupware design.

is a platform for rapidly developing virtual environments that combine two popular forms of collaboration: a 3D collaborative virtual environment fostering meetings, appointments, whiteboard sessions and lectures, along with a 2D development environment including collaborative software design, text editing, and debugging tools. This paper presents novel aspects of the Unicron design and implementation.

In order to facilitate and improve collaboration among co-authors, working in the Web environment, documents must be made seamlessly available to them. Web documents may contain multimedia resources, whose management raises important issues due to the constraints and limits imposed by Web technology. This paper proposes an adaptive support for distributing shared Web documents and multimedia resources across authoring group sites. Our goal is to provide an efficient use of costly Web resources. Distribution is based on the current arrangement of the participating sites, the roles granted to the co-authors and the site capabilities. We formalize key concepts to ensure that system’s properties are fulfilled under the specified conditions and to characterize distribution at a given moment. The proposed support has been integrated into the PIÑAS platform, which allows an authoring group to collaboratively and consistently produce shared Web documents.

Today there exist many frameworks for the development of synchronous groupware applications. Although the domain of these applications is very heterogeneous, existing frameworks provide only limited flexibility to integrate diverse groupware applications in a meaningful way. We identify five variation points that a groupware framework needs to offer in a flexible way in order to facilitate the integration of diverse groupware applications. Based on these variation points, we propose a groupware framework called Agilo that tries to overcome the limited flexibility of existing frameworks by offering multiple realizations of these variation points and providing a modular architecture to simplify the integration of applications and the extensibility and adaptability to different application and integration requirements.

Asynchronous collaborative applications and systems have to deal with complexities associated with interaction nature, idiosyncrasy of groups and technical and administrative issues of real settings. Existing solutions address asynchronous collaboration via simplified and centralized models. In this paper we present LaCOLLA, a fully decentralized middleware for building collaborative applications that provides general purpose collaborative functionality without requiring anyone to provide resources for the whole group. This helps applications to incorporate collaboration support and deal with most complexities derived from groups and its members. The implementation of LaCOLLA follows the peer-to-peer paradigm and pays special attention to the autonomy of its members and to the self-organization of its components. Resources (e.g. storage, task execution) and services (e.g. authorization) are provided by its members, avoiding dependency from third party agents or servers. This work was first validated by simulation. Then we built the middleware and adapted some collaborative applications.

When developing groupware satisfying user requirements is even more difficult than in the context of single-user application development; not only the interaction with the application itself but also the interaction between group members must be respected. Current design methodologies insufficiently focus the designers’ attention to this aspect. Therefore, we propose the that fosters end-user participation, structures the interaction between end-users and developers, and emphasizes the use of a shared language between users and developers.

It is common that, in a long-term asynchronous collaborative activity, groups of users engage in occasional synchronous sessions. In this paper, we discuss the data management requirements for supporting this common work practice. As users interact in different ways in each setting, requirements and solutions often need to be different. We present a data management system that allows to integrate a synchronous session in the context of a long-term asynchronous interaction, using the suitable data sharing techniques in each setting and an automatic mechanism to convert the long sequence of small updates produced in a synchronous session into a large asynchronous contribution. We exemplify the use of our approach with two multi-synchronous applications.

This paper proposes an architectural model to facilitate the design of component-based groupware systems. This architectural model has been defined based on (1) three pre-defined component types, (2) a refinement strategy that relies on these component types, (3) the identification of layers of collaboration concerns, and (4) rules for the coupling and distribution of the components that implement these concerns. Our architectural model is beneficial for controlling the complexity of the development process, since it gives concrete guidance on the concerns to be considered and decomposition disciplines to be applied in each development step. The paper illustrates the application of this architectural model with an example of an electronic voting system.

This paper presents an architecture for distributed synchronous collaborative visualization and modeling applied to the geosciences. Our goal is to facilitate the creation of heterogeneous collaboration sessions, in which participants may use different versions of a core CAD application, configured with specific functionalities and multimedia user interfaces, through the composition of run-time plugins. We describe the domain requirements, the architectural concepts that facilitate the integration of our collaboration plugins with the core application, and the management of communication channels to allow the definition of role-based control policies adapted to specific types of sessions.

Monitoring the remote motion of objects or the control points of objects is one of the most important ways to promote awareness in Internet-based real-time collaborative graphics editing systems. However, such kind of remote control point motion is usually influenced by network jitter which leads to halting and jumping presence. Although motion prediction has been proved effective to complement the negative effect of jitter, the low accuracy of prediction remains a problem. In this paper, we present novel algorithms that can improve the accuracy to restore the remote motion smoothly and immediately. The prediction algorithms have been implemented in CoDesign – a prototype system of collaborative graphics editing. Experiments were carried out to test the effectiveness of the algorithms and the results show that by applying effective remote motion prediction the usability of the system can be greatly enhanced.