Peer assessment has gained growing popularity in education and teaching. Being a learning tool, evaluating their peers can equip learners with skills to develop judgments about what forms high-quality work. There have been however research gaps in the literature showing a lack of adequate work on the investigation of peer assessment in a group-oriented classroom context. The present study inten...

The open and anonymous nature of peer-to-peer system makes it easy to be attacked and abused by some malicious nodes, so it is very important to establish a perfect trust mechanism in peer-to-peer environment. In this paper, we propose a novel group-based trust model in which the trust relationships between entities are divided into trust relationship in group and trust relationship between gro...

Many peer-to-peer (P2P) applications benefi t from node specialization: for example, the use of supernodes, the semantic clustering of media fi les or the distribution of different computing tasks among nodes. We describe simulation experiments with a simple selfi sh re-wiring protocol (SLAC) that can spontaneously self-organize networks into internally specialized groups (or ‘tribes’). Peers w...

We describe “implicit group messaging”: a form of many-to-many message delivery that does not require publishers to enumerate recipients, or recipients to join explicit groups. Instead, publishers specify the characteristics of intended audiences and the system dynamically attempts to deliver messages to all matching members. We study this type of message delivery in the context of peer-to-peer...

This paper proposes several integrated security architecture designs for client-server group communication systems. In an integrated architecture, security services are implemented in servers, in contrast to a layered architecture where the same services are implemented in clients. We discuss the performance and accompanying trust issues of each proposed architecture and present experimental re...