Quality of Service, user perception, eCommerce, server design, internet, web server design As the number of Web users and the diversity of Web applications continues to explode, Web Quality of Service (QoS) is an increasingly critical issue in the domain of e-Commerce. This paper presents experiments designed to estimate users' tolerance of QoS in the context of e-commerce. In addition to objective measures we discuss contextual factors that influence these thresholds and show how users' conceptual models of Web tasks affect their expectations. We then show how user thresholds of tolerance can be taken into account when designing web servers. This integration of user requirements for QoS into systems design is ultimately of benefit to all stakeholders in the design of Internet services. AbstractAs the number of Web users and the diversity of Web applications continues to explode, Web Quality of Service (QoS) is an increasingly critical issue in the domain of e-Commerce [re]. This paper presents experiments designed to estimate users' tolerance of QoS in the context of e-commerce. In addition to objective measures we discuss contextual factors that influence these thresholds and show how users' conceptual models of Web tasks affect their expectations. We then show how user thresholds of tolerance can be taken into account when designing web servers. This integration of user requirements for QoS into systems design is ultimately of benefit to all stakeholders in the design of Internet services.

Shared networks, such as the Internet, are fast becoming able to support heterogeneous applications and a diverse user community. In this climate, it becomes increasingly likely that some form of pricing mechanism will be necessary in order to manage the Quality of Service (QoS) requirements of different applications. So far, research in this area has focussed on technical mechanisms for implementing QoS and charging. This paper reports a series of studies in which users' perceptions of QoS, and their attitudes to a range of pricing mechanisms, were investigated. We found that users' knowledge and experience of networks, and the real-world Task they perform with applications, determine their evaluation of QoS and attitude to payment. Users' Payment Behavior is governed by their level of Confidence in the performance of salient QoS parameters. User Confidence, in turn, depends on a number of other factors. In conclusion, we argue that charging models that undermine User Con$dence are not only undesirable from the users' point of view, but may also lead to user behavior that may have a negative impact on QoS.

Multimedia communication has gained increasing attention, both from the application side and the network provider side. While resource provisioning for QoS support in packet switched networks has lead to the design and development of sophisticated QoS architectures, notably ATM, IntServ or DiffServ, research has not exactly been user or application-context centered. In the cause of the evolution of QoS architectures, the integrated service network approach has lost momentum, and with it, the notion of QoS guarantees. Differentiation of QoS classes within the DiffServ framework is based on the definition of various per-hop behaviors. What is currently missing is a technique for specification and mapping of application and user QoS preferences onto evolving service profiles. In addition, adaptation of applications (and users) is becoming increasingly important in the face of dominating weak QoS-assurance paradigms, both in wireline and wireless environments. As a prerequisite, this paper investigates cognitive and perceptive conditioning of users and applications in a situated setting. The contribution of this paper is twofold: First, essential empirical results on user QoS preferences and QoS graduations are presented, and second, methodological foundations are laid for investigating user-centered QoS.

Abstract. The field of molecular biology is in a remarkably rapid period of change, as the genome sequencing projects and new experimental technologies have generated an explosion of data To analyze and draw insights from the vast amounts of information, biologists use a new generation of bioinformatics software tools, often working closely with mathematicians and computer scientists There are elements of both collision and convergence in these interdisciplinary encountersWe conducted user studies with biologists engaged in investigating the molecular basis of disease. We describe several issues that arise in this collision/convergence of disciplines, drawing on the notion of boundary objects m-the-makmg. We provide recommendations on building technology for people whose work now sits at the crossroads of diverse and rapidly changing scientific fields.