This paper presents a descriptive account of the social practices surrounding the iTunes music sharing of 13 participants in one organizational setting. Specifically, we characterize adoption, critical mass, and privacy; impression management and access control; the musical impressions of others that are created as a result of music sharing; the ways in which participants attempted to make sense of the dynamic system; and implications of the overlaid technical, musical, and corporate topologies. We interleave design implications throughout our results and relate those results to broader themes in a music sharing design space. Author Keywords iTunes, music sharing, discovery

Abstract. Researchers and practitioners are still trying to find effective ways to model and test Web applications. This paper proposes a system-level testing technique that combines test generation based on finite state machines with constraints. We use a hierarchical approach to model potentially large Web applications. The approach builds hierarchies of Finite State Machines (FSMs) that model subsystems of the Web applications, and then generates test requirements as subsequences of states in the FSMs. These subsequences are then combined and refined to form complete executable tests. The constraints are used to select a reduced set of inputs with the goal of reducing the state space explosion otherwise inherent in using FSMs. The paper illustrates the technique with a running example of a Web-based course student information system and introduces a prototype implementation to support the technique.

Abstract: This study examines the implicit and explicit heuristics and usability evaluation processes utilized by a leading game developer. Five people from a single game team, each contributing in a different way to the game development process, were observed for one business day and interviewed. At the time of this study, the participating game team was at the tail end of their first month of prototyping in the pre-production phase of development. The data collected and literature reviewed combine to suggest that instituting more formal usability evaluation processes could be helpful to the game development process. The heuristics created in this study are a starting point for the construction of a standard list of game heuristics for use by the game development community. 2 TABLE OF CONTENTS

Rapid improvements in network bandwidth, cost, and ubiquity combined with the security hazards and high total cost of ownership of personal computers have created a growing market for thin-client computing. We introduce THINC, a virtual display architecture for high-performance thin-client computing in both LAN and WAN environments. THINC virtualizes the display at the device driver interface to transparently intercept application display commands and translate them into a few simple low-level commands that can be easily supported by widely used client hardware. THINC’s translation mechanism efficiently leverages display semantic information through novel optimizations such as offscreen drawing awareness, native video support, and server-side screen scaling. This is integrated with an update delivery architecture that uses shortest command first scheduling and non-blocking operation. THINC leverages existing display system functionality and works seamlessly with unmodified applications, window systems, and operating systems. We have implemented THINC in an X/Linux environment and compared its performance against widely used commercial approaches, including Citrix MetaFrame, Microsoft RDP, GoToMyPC, X, NX, VNC, and Sun Ray. Our experimental results on web and audio/video applications demonstrate that THINC can provide up to 4.8 times faster web browsing performance and two orders of magnitude better audio/video performance. THINC is the only thin client capable of transparently playing full-screen video and audio at full frame rate in both LAN and WAN environments. Our results also show for the first time that thin clients can even provide good performance using remote clients located in other countries around the world.

This paper proposes a transformation of the Cognitive Walkthrough (CW), a theory-based usability inspection method that has proven useful in designing applications that support use by exploration. The new Cognitive Walkthrough for the Web (CWW) is superior for evaluating how well websites support users ’ navigation and information search tasks. The CWW uses Latent Semantic Analysis to objectively estimate the degree of semantic similarity (information scent) between representative user goal statements (100-200 words) and heading/link texts on each web page. Using an actual website, the paper shows how the CWW identifies three types of problems in web page designs. Three experiments test CWW predictions of users’ success rates in accomplishing goals, verifying the value of CWW for identifying these usability problems.

The large number of Web pages on many Web sites has raised navigational problems. Markov chains have recently been used to model user navigational behavior on the World Wide Web (WWW). In this paper, we propose a method for constructing a Markov model of a Web site based on past visitor behavior. We use the Markov model to make link predictions that assist new users to navigate the Web site. An algorithm for transition probability matrix compression has been used to cluster Web pages with similar transition behaviors and compress the transition matrix to an optimal size for efficient probability calculation in link prediction. A maximal forward path method is used to further improve the efficiency of link prediction. Link prediction has been implemented in an online system called ONE (Online Navigation Explorer) to assist users'navigation in the adaptive Web site.

We describe the development of a computational cognitive model that explains navigation behavior on the World Wide Web. The model, called SNIF-ACT (Scent-based Navigation and Information Foraging in the ACT cognitive architecture), is motivated by Information Foraging Theory (IFT), which quantifies the perceived relevance of a Web link to a user’s goal by a spreading activation mechanism. The model assumes that users evaluate links on a Web page sequentially and decide to click on a link or to go back to the previous page by a Bayesian satisficing model (BSM) that adaptively evaluates and selects actions based on a combination of previous and current assessments of the relevance of link texts to information goals. SNIF-ACT 1.0 utilizes the measure of utility, called information Wai-Tat Fu is an applied cognitive scientist with interests in human–computer interaction, cognitive modeling, information seeking, interactive decision making, and cognitive skill acquisition; he is an Assistant Professor in the Human Factors Division and Beckman Institute of Advanced Science and Technology at the University

Continuing advances in hardware technology have enabled the proliferation of faster, cheaper, and more capable personal computers. Users of all backgrounds rely on their computers to handle ever-expanding information, communication, and computation needs. As users spend more time interacting with their computers, it is becoming increasingly important to archive and later search the knowledge, ideas and information that they have viewed through their computers. However, existing state-of-the-art web and desktop search tools fail to provide a suitable solution, as they focus on static, accessible documents in isolation. Thus, finding the information one has viewed among the ever-increasing and chaotic sea of data available from a computer remains a challenge. This dissertation introduces DejaView, a personal virtual computer recorder that enhances personal computers with the ability to process display-centric content to help users with all the information they see through their computers. DejaView

The growth of the World Wide Web and the accelerated development of web sites and associated web technologies has resulted in a variety of maintenance problems. The maintenance problems associated with web sites and the WWW are examined. It is argued that currently web sites and the WWW lack both data abstractions and structures that could facilitate maintenance. A system to analyse existing web sites and extract duplicated content and style is described here. In designing the system, existing Reverse Engineering techniques have been applied, and a case for further application of these techniques is made in order to prepare sites for their inevitable evolution in future.

This research examines the pattern of Web information seeking in four groups of nurses with different combinations of domain expertise and Web expertise. Protocols were gathered as the nurses carried out information-seeking tasks in the domain of osteoporosis. Domain and Web novices searched breadth-first and did little or no evaluation of the results. Domain expert/Web novices also searched breadth-first but evaluated information more thoroughly using osteoporosis knowledge. Domain novice/Web experts searched in a mixed, breadth-first/depth-first pattern and attempted to evaluate information using general criteria. Domain expert/Web experts carried out depth-first searches, following deep trails of information and evaluated information based on the most varied and sophisticated criteria. The results suggest that there are distinct differences in searching patterns related to expertise. Implications of these findings and suggestions for future research are provided.