In this paper we present the case for using specifically configured protocol stacks geared towards human requirements in the delivery of distributed multimedia. We define Quality of Perception (QoP) as representing the user side of the more technical and traditional Quality of Service (QoS). QoP is a term which encompasses not only a user's satisfaction with the quality of multimedia presentations, but also his/her ability to analyse, synthesise and assimilate the informational content of multimedia displays. The Dynamically Reconfigurable Protocol Stacks (DRoPS) architecture supports low cost reconfiguration of individual protocol mechanisms in an attempt to best maintain QoP in connections where the provided QoS fluctuates unpredictably. Results show that DRoPS can be used to improve on the QoP provided by legacy protocol stacks (TCP/IP, UDP/IP), especially in the case of dynamic and complex sequences.

Goals and content: This tutorial will explain how video/audio networks are built and how they are typically used. An introduction to the concepts and terminology of video, audio, digital compression, transmission networks, and station equipment is provided. Participants can expect to learn what people like and dislike about these systems, and the avenues that are being explored to overcome their shortcomings. About the instructors: Robert Fish is the Executive Director of the Multimedia Intelligent Networking Research Department at Bellcore. Robert Kraut is professor of social psycology and human-computer interaction at Carnegie Mellon University.

This field experiment investigates individual, structural and social influences on the use of two video telephone systems. One system flourished, while an equivalent system died. We use a time series design and multiple data sources to test media richness theory, critical mass theory, and social influence theories about new media use. Results show that the fit between tasks and features of the communications medium influences use to a degree, but cannot explain why only one system survived. Critical mass—the numbers of people one can reach on a system—and social influence—the norms that grow up around a new medium—can explain this phenomenon.

Collaborations in organizations thrive on communication that is informal because informal communication is frequent, interactive, and expressive. Informal communication is crucial for the coordination of work, learning an organization's culture, the perpetuation of the social relations that underlie collaboration, and, in general, any situation that requires communication to resolve ambiguity. Informal communication is traditionally mediated by physical proximity, but physical proximity cannot mediate in geographically distributed organizations. The research described here evaluates the adequacy of a version of a desktop video/audio conferencing system for supporting informal communication in a research and development laboratory. The evaluation took place during a trial in which the system was used by summer employees and their supervisor-mentors. While the system was used frequently, the most common uses and users' assessments suggest that it was used more like a telephone or electronic mail than like physically mediated face-to-face communication. However, some features of its use transcended traditional media and allowed users to gain awareness of their work environment. The paper concludes with a discussion of requirements for successful technology to support informal communication.

This paper reviews the design and implementation of several video telephony systems at Bellcore as a case study in iterative design.In contrast to single user compuer applications, communication systems consists of both the interconnection technology and the people who are interconnected.From a user's point of view, the capabilities provided by the system, the rules for its use, and its reaction to their actions depend jointly on what its developers implemented and how other users behave.This fact has wide-ranging implications for system design, use, and evaluation.In reviewing our design experience, we identify four dilemmas for iterative design that flow from the inherently social nature of communication systems.We conclude with methodological and theoretical suggestions to supplement conventional iterative design principles as applied to communications systems.

Modalities such as face-to-face meetings permit rich communication, which involves both expressiveness and interactivity. Modalities such as text annotation or electronic mail, however, limit both. Contingency theory, as applied to collaborative writing, says that as the equivocality of the writing task increases, communication modalities that support rich communication are more likely to be used. In addition, it says that if these modalities are used, equivocal tasks can be carried out with greater ease and better results. This article explores these hypotheses using multiple data sources: an interview study tracing the history of 55 published collaborative articles, two field experiments comparing the use of face-to-face communication and electronic mail as media for collaborative writing, and a laboratory experiment comparing voice and text as media for annotating documents. Taken together, the findings of these investigations are loosely consistent with a contingency theory of media use, but they suggest that careful measures of task characteristics are needed to obtain a detailed understanding of the effects of particular task/technology combinations. Further, they indicate that it may be important to consider the distinction between the interactivity and expressiveness components of media richness in making decisions about what technologies to buy or build.

Both theory and data suggest that that richer, more informal, and more interactive media should be better suited for handling the more complex, equivocal, and emotional aspects of collaborative tasks.To test this hypothesis, we constructed an experiment in which participants were required to make either written or spoken annotations to a document to help a fictional co-author revise it.We seeded relatively error-free texts with errors of different scope .The results provide strong evidence that a richer --in the sense of a more expressive -medium is especially valuable for the more complex, controversial, and social aspects of a collaborative task.Subjects stated that they preferred to use voice to comment on higher-level issues in a document and to use text to deal with lower-level problems of spelling and grammar.When subjects' annotation modalities were restricted, using written annotations led them to comment on more local problems in the text, while using speech Icd lhem to comment on higher level concerns.When lhey did use written annotations to comment on global problems, they were less successful than when they used spoken annotations.Finally, when they offered spoken annotations, they were more likely to add features, such as personal pronouns and explanation, that made their comments more equivocal and socially communicative.These results indicate the uses to which systems that provide voice annotation are likely to be put.

Article Free Access Share on The VideoWindow system in informal communication Authors: Robert S. Fish Bellcore, 445 South Street, Morristown, NJ Bellcore, 445 South Street, Morristown, NJView Profile , Robert E. Kraut Bellcore, 445 South Street, Morristown, NJ Bellcore, 445 South Street, Morristown, NJView Profile , Barbara L. Chalfonte Bellcore, 445 South Street, Morristown, NJ Bellcore, 445 South Street, Morristown, NJView Profile Authors Info & Claims CSCW '90: Proceedings of the 1990 ACM conference on Computer-supported cooperative workSeptember 1990 Pages 1–11https://doi.org/10.1145/99332.99335Online:01 September 1990Publication History 177citation2,054DownloadsMetricsTotal Citations177Total Downloads2,054Last 12 Months142Last 6 weeks20 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Quilt is a computer-based tool for collaborative document production. It provides annotation, messaging, computer conferencing, and notification facilities to support communication and information sharing among the collaborators on a document. Views of a document tailored to individual collaborators or to other of the document's users are provided by Quilt based on the user's position in a permission hierarchy that reflects an extensible set of social roles and communication types. This paper illustrates how Quilt could be used by collaborators to produce a document.