The problems of designing large software systems were studied through interviewing personnel from 17 large projects. A layered behavioral model is used to analyze how three lgf these problems-the thin spread of application domain knowledge, fluctuating and conflicting requirements, and communication bottlenecks and breakdowns-affected software productivity and quality through their impact on cognitive, social, and organizational processes.

In this chapter I review empirical studies directly testing the

Large networks, having thousands of vertices and lines, can be found in many different areas, e. g: genealogies, flow graphs of programs, molecule, computer networks, transportation networks, social networks, intra/inter organisational networks ... Many standard network algorithms are very time and space consuming and therefore unsuitable for analysis of such networks. In the article we present some approaches to analysis and visualisation of large networks implemented in program Pajek. Some typical examples are also given. 1 Introduction Pajek (Slovene word for Spider) is a program, for Windows (32 bit), for analysis of large networks. It is freely available, for noncommercial use, at its homepage: http://vlado.fmf.uni-lj.si/pub/networks/pajek/ Large networks can be found in many different areas. Usually they are produced automatically, using computers, from different data sources that are already available in computer readable form. For example: large genealogies (genea...

It is frequently suggested that work groups that have computer technology to support activities such as text editing, data manipulation, and communication develop systematically different structures and working processes from groups that rely on more conventional technologies such as memos, phone calls, and meetings. However, cross-sectional or retrospective research designs do not allow this hypothesis to be tested with much power. This field experiment created two task forces, each composed equally of recently retired employees and employees still at work but eligible to retire. They were given the identical tasks of preparing reports for their company on retirement planning issues, but they were randomly assigned to different technology conditions. One group had full conventional office support; the other had, in addition, networked microcomputers with electronic mail and routine office software. Structured interviews were conducted four times during the year-long project; in addition, electronic mail activity was logged in the on-line group. Although both groups produced effective reports, the two differed significantly in the kind of work they produced, the group structures that emerged, and evaluations of their own performance. Although the standard group was largely dominated by the employees through the extensive reliance on informal meetings, the electronic technology used by the other task force allowed the retirees to exercise primary leverage. We conclude that use of computer support for cooperative work results in both quantitative and qualitative changes but that effective participation in such electronically supported groups requires significant invest-

Agent-based systems are no longer contained within the boundaries of a single, small agent organization. To meet the demands of large-scale system implementations, agent organizations must deal with environmental forces, interact with other agent organizations, and know how they affect individual agents. In this paper, we look to social and organizational systems theory as a source of inspiration. Many of these techniques have been successful for a hundreds and thousands of years. We believe that the designers of agent-based systems can learn a great deal from organization designers. In the first of a series, this paper examines the notion of role and its implications on how agents might behave in group settings.

This paper identifies hyperlink network analysis (HNA) as a newly emerging methodology. It suggests that social (or communication) structures on the web may be analyzed based on the hyperlinks among websites. Hyperlink network analysis has advantages in describing emerging structures among social actors on the web. In order to examine what constitutes hyperlink network analysis, this paper reviews prior research on the topic. Further, it describes the data-gathering techniques for those interested in hyperlink network analysis.

Theories of the fertility transition now routinely reserve a place for diffusion effects (Mason 1997). Such effects arise because individuals are themselves members of larger groups. The information that is held by group members, the choices they make, and the outcomes that flow from them—all these can exert a powerful influence on individual incentives to innovate. In settings in which fertility has been high, such innovation may take the form of modern contraceptive adoption and fertility limitation. Under certain conditions, the individual-to-group connections establish pathways along which such innovative demographic behavior can diffuse. What empirical evidence supports the view that diffusion matters to fertility decline? As we will show, proponents can find in the fertility literature numerous hints and indirect suggestions of a role for diffusion. Until very recently, however, the available data were insufficient to withstand rigorous scientific scrutiny. Over the past several years, several groups of researchers have initiated longitudinal studies that promise to better illuminate the contribution of diffusion. 1 With the study of diffusion effects about to enter a new phase, this is an appropriate moment to take stock of what has been learned and to describe the new research directions that lie ahead. Our aim in this paper is threefold: to assemble the disparate concepts of the diffusion perspective into a coherent whole; to

The general purpose was to make senior secondary school teachers of English as a foreign language and their students aware of the possibilities of some pedagogical applications of Information Technology in foreign language (FL) teaching. The specific purpose was to study how computer-mediated, foreign language referential communication, carried out via communications networks and electronic mail (e-mail), could be adapted to FL teaching in Finnish senior secondary schools. The research model combined foreign language education and Information Technology (communications networks and e-mail). The scientific problem was built on communicativeness as a general objective in FL teaching and communications networks contributing to simulating communicativeness in FL classrooms. At the operational level, this led to introducing communications networks as a technological innovation into FL classrooms.

…for its continued progress in building a culture of regional cooperation and decision-making to increase the quality of life of member nations, The development of a Regional Spatial Data Infrastructure (Regional SDI) is much more challenging than the development of a National SDI initiative within a nation. This is mainly because of the voluntary nature of cooperation at a multi-national level and participation in a Regional SDI initiative. As a result, despite considerable interest and activities, the development of an effective and comprehensive Asia-Pacific Regional Spatial Data Infrastructure (APSDI) is hampered by a lack of support from member nations which results in this initiative remaining only an innovative concept. Based on this situation, the aim of this research is to design an improved conceptual model for Regional SDI and an implementation strategy. It is proposed that this problem can be partly addressed by increasing the level of awareness about the nature and value of SDIs; improving the SDI conceptual model to better meet the needs of nations; and by identifying key factors that facilitate development by better understanding the

this article will attempt a fresh conceptualization of source. It will first explicate the concept of source as used in past communication research. It will identify key conceptions of source in the literature and use them to create a typology. The strength of the resulting typology will be evaluated along three criteria: (a) It should apply to all media, particularly new online media; (b) the distinctions in the typology should have ontological rationale; and (c) they should engender psychological differences among media audiences