A MODEL FOR PREDICTING THE PERFORMANCE OF IP VIDEOCONFERENCING

With the incorporation of free desktop videoconferencing (DVC) software on the majority of the world's PCs, over the recent years, there has, inevitably, been considerable interest in using DVC over the Internet. The growing popularity of DVC increases the need for multimedia quality assessment. However, the task of predicting the perceived multimedia quality over the Internet Protocol (IP) networks is complicated by the fact that the audio and video streams are susceptible to unique impairments due to the unpredictable nature of IP networks, different types of task scenarios, different levels of complexity, and other related factors. To date, a standard consensus to define the IP media Quality of Service (QoS) has yet to be implemented. The thesis addresses this problem by investigating a new approach to assess the quality of audio, video, and audiovisual overall as perceived in low cost DVC systems. The main aim of the thesis is to investigate current methods used to assess the perceived IP media quality, and then propose a model which will predict the quality of audiovisual experience from prevailing network parameters. This thesis investigates the effects of various traffic conditions, such as, packet loss, jitter, and delay and other factors that may influence end user acceptance, when low cost DVC is used over the Internet. It also investigates the interaction effects between the audio and video media, and the issues involving the lip sychronisation error. The thesis provides the empirical evidence that the subjective mean opinion score (MOS) of the perceived multimedia quality is unaffected by lip synchronisation error in low cost DVC systems. The data-gathering approach that is advocated in this thesis involves both field and laboratory trials to enable the comparisons of results between classroom-based experiments and real-world environments to be made, and to provide actual real-world confirmation of the bench tests. The subjective test method was employed since it has been proven to be more robust and suitable for the research studies, as compared to objective testing techniques. The MOS results, and the number of observations obtained, have enabled a set of criteria to be established that can be used to determine the acceptable QoS for given network conditions and task scenarios. Based upon these comprehensive findings, the final contribution of the thesis is the proposal of a new adaptive architecture method that is intended to enable the performance of IP based DVC of a particular session to be predicted for a given network condition

Getting on the E List: E-Mail Use in a Community of Service Provider

This case examines how a community of organizations providing service to people experiencing homelessness made use of an electronic mail list. Current economic conditions have encouraged organizations in various sectors—including nonprofits—that might normally compete for scarce resources to collaborate with one another to increase their chances of survival. One set of tools likely to be of value in such relationships includes various online discussion technologies. An examination of this community’s email list use over a three-year period suggests a somewhat complex picture regarding technology use. More specifically, some issues both constrain and enable use. Additionally, seemingly basic and minimal uses of the list provided not only the greatest functionality for the users, but also led to several unanticipated consequences for those involved

MULTIMODALITY IN COMPUTER MEDIATED COMMUNICATION

2002/2003XVI Ciclo1974Versione digitalizzata della tesi di dottorato cartacea

Virtual workplaces : when metaphors breakdown

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1998.Includes bibliographical references (leaves 79-81).Our model of work is shaped by the places we choose to work and the tools we choose to work with. As we introduce new technologies and build new environments our model is changing. Today's virtual workplaces are grounded in models of work that have been reformed from our experiences using current technology in physical workspace. However we are discovering opportunities and possibilities for work in collaborative, virtual environments that question physical models. Emerging patterns of distributed collaboration in persistent virtual environments are changing the way we work in time and space, recasting our notion of workplace. Virtual workplaces are interpreted and experienced through metaphors that describe a space of potential for work occurrences. Through the lens of metaphors, this research focuses on breakdowns between collaborative work and the environment in which work occurs. If what we understand and predict is based on what we already know, then by examining the breakdowns between design and use of collaborative environments we can illuminate the space of possibilities for collaborative work.by Thomas W.I. Gallemore.M.S

Using Games as a Means for Collaboration

The availability of a good interface for online user collaboration has been a sore point for most collaboration applications to date. While MUD's, MOO's, IRC and other chat applications are well suited to impersonal communication, the meaning of a single message can often be misconstrued or misunderstood, and the effort often required to learn control of a new application while understanding navigation in a virtual world, can be difficult to overcome. The Nexus promises to aid in the intuitive act of communication, interaction and movement and in the process enhance the collaboration experience for the user, through the use of a game engine

Virtual schooling service: Productive pedagogies or pedagogical possibilities?

This article reports on an evaluation of a virtual schooling innovation in an Australian context. The Virtual Schooling Service Pilot uses online technologies to deliver senior school subjects in both synchronous and asynchronous modes of delivery. The purpose of the study was to analyze the organizational, pedagogical, and technological efficacy of the innovation for the purpose of exploring the feasibility of mainstreaming virtual delivery for secondary schooling. Although the Virtual Schooling Service was important in maintaining curricular provision, application of the Productive Pedagogies framework showed that the innovation held pedagogical potential that remained unrealized

Distributed software design for collaborative learning system over the Internet

Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (leaves 166-168).by Christine Hui Su.S.B.and M.Eng

Meeting the Needs of the Nontraditional Student:: A Study of the Effectiveness of Synchronous Online Writing Center Tutorials

In the fall of 2007, 3.9 million students took at least one online course, reflecting an online education growth rate of 12.9 percent. Many online students are nontraditional, possessing one or more of the following characteristics: delayed enrollment, part time attendance, full-time worker, financially independent as related to financial aid, dependents other than a spouse, single parent, a GED or did not finish high school. While these students bring diversity and life experience to the classroom, they are often ill-prepared for college writing. Though they need help, hectic schedules make it difficult to meet with a writing consultant. This study investigates whether synchronous writing center tutorials can effectively address this client population's needs. Currently, there is a dearth of scholarship relating to online writing tutorials, particularly synchronous tutorials. This two-year study of 189 face-to-face clients and 90 online clients employs quantitative and qualitative research to determine (1) the demographic profile of online users, (2) reasons clients meet online, (3) help sought online, (4) online client preparation, (5) client perceptions of online sessions, and (6) advantages and disadvantages of online sessions. Data were culled from a client questionnaire, online session logs, and consultant and client interviews. Statistically significant differences in client demographics between face-to-face and online users were found in age, ethnicity, and gender: online clients are younger, are more likely to be white, and are more likely to be male. Clients meet online primarily for convenience; however, there is no correlation between distance from campus and online client usage. There were no significant differences in client preparation. Spelling was the only statistically significant category in help sought: online clients seek more spelling help than their face-to-face counterparts. Face-to-face and online clients both viewed their sessions as successful with no statistically significant difference between the groups. Over one-third of clients reported technical problems during their session, and some clients expressed a preference for the emphatic cues found in face-to-face consultations. Advantages of online sessions included assistance with word processing features, the ability to make revisions to the working document, and the ability to record the session

Computer supported interaction in distributed design teams

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1998.Includes bibliographical references (leaves ).by Karim Mohie El Din Hussein.Sc.D