This paper analyzes the scalability of Instant Messaging & Presence (IM&P) architectures. We take a queueing-based modelling and analysis approach to find the bottlenecks of the current IM&P architecture at the Dutch social network Hyves, as well as of alternative architectures. We use the Hierarchical Evaluation Tool (HIT) to create and analyse models analytically. Based on these results, we r...

This case study explores the role of the online instructor and how they influence student satisfaction. While there has been a substantial body of literature on what impacts on student satisfaction when students study online, there is far less literature focussing on how the instructor mediates this satisfaction, in particular satisfaction related to quality of feedback and teaching. This case ...

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as refer...

We define social reciprocity as the act of demonstrating one’s disapproval, at some personal cost, for the violation of widely-held norms (e.g., don’t free ride). Social reciprocity differs from standard notions of reciprocity because social reciprocators intervene whenever a norm is violated and do not condition intervention on potential future payoffs, revenge, or altruism. Instead, we posit ...

Numerous studies address the ability of the computer-mediated communication (CMC) medium to carry social cues, e.g., social presence. This paper proposes to expand the study of social cues to include interpersonality measures directed toward messages within the CMC medium. Interpersonality is conceptualized as the joint measure of anticipated feedback and message coherence, factors that disting...

The purpose of this research-in-progress paper is to explore factors affecting users’ participation in microblogging. Based on literature review and the stimulus-organism-response (S-O-R) framework, a conceptual model is proposed to depict the relationships between the features of micro-blogging services and users’ behavior. Specifically, the features of micro-blogs such as subscription, broadc...

We study videoconferencing for meetings with some co-located participants and one remote participant. A standard Skype-like interface for the remote participant is compared to a more immersive 3D interface that conveys gaze directions in a natural way. Experimental results show the 3D interface is promising: all significant differences are in favor of 3D and according to the participants the 3D...

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as refer...

The behavior of others and the price of giving are two important determinants of contributions to public goods. This paper tests in two field experiments, whether men and women differ in their reaction to either a change in the behavior of the average group behavior or the price of giving, i.e. a matching mechanism. The results of the field experiment show that men and women do not differ in th...

The present research aimed to employ dynamic and static emotions as social cues in e-learning environments for computers to be able to convey social presence and increase children’s motivation with learning. To understand how children of different gender react to the two types of emoticon in e-learning environment, a math problem-solving practice program was designed to test their reactions. Th...