One of the potent personalization technologies powering the adaptive web is collaborative filtering. Collaborative filtering (CF) is the process of filtering or evaluating items through the opinions of other people. CF technology brings together the opinions of large interconnected communities on the web, supporting filtering of substantial quantities of data. In this chapter we introduce the core concepts of collaborative filtering, its primary uses for users of the adaptive web, the theory and practice of CF algorithms, and design decisions regarding rating systems and acquisition of ratings. We also discuss how to evaluate CF systems, and the evolution of rich interaction interfaces. We close the chapter with discussions of the challenges of privacy particular to a CF recommendation service and important open research questions in the field.

Web-based learning is primarily a lonesome activity, even when it involves working in groups. This is due to the fact that the majority of web-based learning relies on asynchronous forms of interacting with other people. In most of the cases, the chat discussion is the only form of synchronous interaction that adds to the feeling that there are other people present in the environment. EDUCO is a system that tries to bring in the sense of other users in a collaborative learning environment by making the other users and their the navigation visible to everyone else in the environment in real-time. The paper describes EDUCO and presents the first empirical evaluation as EDUCO was used in a university Course.

Many of the possibilities of Web-based education are still unexplored. It seems that novel ways of thinking about both learning and technology are needed to get beyond the limitations of the traditional classroom setting. In this paper we introduce EDUCOSM, which focusses on the possibilities of collaboration and the open-ended nature of the Web. Its main features include sharing and annotation of arbitrary Web-pages, and an adaptive desktop for accessing the evolving contents of the system. EDUCOSM has been used in a real Web-based course, and the experiences are discussed along with a description of the tool. Although the approach requires both the teacher and the students to rethink their roles, the feedback received so far has been encouraging. 1.

Tools to enable joint annotation help in collaborative knowledge building in elearning.

OurWeb is a system designed for on-line communities to foster engagement into purposeful activities associated with collaboration. In this paper we present the features and functionality of OurWeb, and report the experiences acquired from a university course, where the course structures were designed to emulate an on-line community and the students were required to act as members of a learning community. The experiences from the course suggest that enhancing interactions between the community members using novel tools is fruitful.

Student-centred learning can be used in Web-courses to increase student activity, motivation and commitment. EDUCO is a system for student-centred learning, both for the learners and the teachers. Students can use EDUCO within a standard web-browser to navigate towards useful information and Web-resources gathered into the system. The key issue is that every participant can see everyone else in the system and their navigational steps, so that the feeling of student companions taking part in the same tasks is increased. The implications of this type of social navigation are discussed along with the description of the system itself. 1.

In this paper, we investigate the architecture for visual social navigation systems, especially those used in scientific literature. We identify the requirements for effective visualization of reputation and recommendation, two notions that underlie most social navigation systems. We present several designs of visual emphasis techniques addressing the dimension and scales of reputation, and two sets of icons for effectively distinguishing recommended items. The results of two user studies are then discussed, which provided validation for our non-linear emphasis methods to represent reputation, and for choosing optimal icons for recommended items. Based on these findings, we present a re-design for the NEC Research Institute ResearchIndex (Citeseer), a concrete case of reputation based recommendation system.

Introduction The World Wide Web has implied an explosion in network-mediated information exchange. Its ubiquitous nature and technical strengths, in particular the flexible hypermedia document format and the general communication protocol, have given users a powerful infrastructure for sharing knowledge as well as for interactive communication. This has created new research questions with respect to how people conceptualize the Web, and how the use of this medium is embedded in their professional activities. This chapter investigates implications of Web-based information exchange for people within knowledge-oriented professions. Our point of departure is a current project on knowledge, communication and context in electronic networks (KnowHow). People in knowledge-intensive professions, such as researchers, technical developers, teachers, and librarians, typically have a continuous need for updated knowledge within their area of expertise, which necessitates contacts with others both