The debate concerning how many participants represents a sufficient number for interaction testing is well-established and long-running, with prominent contributions arguing that five users provide a good benchmark when seeking to discover interaction problems. We argue that adoption of five users in this context is often done with little understanding of the basis for, or implications of, the decision. We present an analysis of relevant research to clarify the meaning of the five-user assumption and to examine the way in which the original research that suggested it has been applied. This includes its blind adoption and application in some studies, and complaints about its inadequacies in others. We argue that the five-user assumption is often misunderstood, not only in the field of Human-Computer Interaction, but also in fields such as medical device design, or in business and information applications. The analysis that we present allows us to define a systematic approach for monitoring the sample discovery likelihood, in formative and summative evaluations, and for gathering information in order to make critical decisions during the interaction testing, while respecting the aim of the evaluation and allotted budget. This approach -- which we call the Grounded Procedure -- is introduced and its value argued.

This paper profiles the types of research activity that have been published in EJIS from 1997 to 2007. Our analysis includes variables such as the most productive authors, citation analysis, universities associated with the most research publications, geographic diversity, authors’ background, subject areas most often investigated, unit of analysis and research methodologies. The classification of the topics and methodologies used by the most highly published authors will help prospective authors gauge whether their paper is suitable for EJIS. The major geographical source of information system (IS) research published in EJIS is from AIS region 2 (Europe, the Middle East and Africa), but with a substantial AIS region 1 (American-based researchers and universities) and AIS region 3 (Asia–Pacific) contribution. The most common research method used is the case study approach, with other methods such as surveys and library research also used frequently. IS management and IS development are the two most researched IS topics published in EJIS. This research and results reported in this paper are comparable with a previous paper published about the Information Systems Journal. Any further such studies will thus be able to make similar comparisons between these journals and any others that have subsequently been covered in this way. The paper concludes with the need for more substantive research on the topic if journal comparisons are to achieve their potential.

Graphical representation may provide effective means of making sense of the complexity and sheer volume of data produced by DNA microarray experiments that monitor the expression patterns of thousands of genes simultaneously. The ability to use ldquoabstractrdquo graphical representation to draw attention to areas of interest, and more in-depth visualizations to answer focused questions, would enable biologists to move from a large amount of data to particular records they are interested in, and therefore, gain deeper insights in understanding the microarray experiment results. This paper starts by providing some background knowledge of microarray experiments, and then, explains how graphical representation can be applied in general to this problem domain, followed by exploring the role of visualization in gene expression data analysis. Having set the problem scene, the paper then examines various multivariate data visualization techniques that have been applied to microarray data analysis. These techniques are critically reviewed so that the strengths and weaknesses of each technique can be tabulated. Finally, several key problem areas as well as possible solutions to them are discussed as being a source for future work.

Security software is often difficult to use thus leading to poor adoption and degraded security. This paper describes a usability study that was conducted on the software 'Polaris'. This software is an alpha release that uses the Principle of Least Authority (POLA) to deny viruses the authority to edit files. Polaris was designed to align security with usability. The study showed that despite this aim, usability problems remained, especially when the study participants had to make security related decisions. They also showed apathy towards security, and knowingly compromised their security to get work done faster. This study also demonstrates the difficulty in achieving security and usability alignment when the usability is a post hoc consideration added to a developed product, rather than being integrated from the start. The alleviation of usability problems from security software proposed in this paper are threefold: reducing the burden on the user to make security related decisions, counteracting user's apathy by ensuring that the fast way of doing things is the secure way, and integrating security software with the operating system throughout development.

Abstract Knowledge domain visualization is a visual exploratory approach to the study of the development of a knowledge domain. In this study, we focus on the practical issues concerning modeling and visualizing scientific revolutions. We study the growth patterns of specialties derived from citation and cocitation data on string theory in physics. Special attention is given to the two superstring revolutions since the 1980s. The superstring revolutions are visualized, animated, and analyzed using the general framework of Thomas Kuhn's structure of scientific revolutions. The implications of taking this approach are discussed.

Knowledge discovery and data mining commonly rely on finding salient patterns of association from a vast amount of data. Traditional citation analysis of scientific literature draws insights from strong citation patterns. Latent domain knowledge, in contrast to the mainstream domain knowledge, often consists of highly relevant but relatively infrequently cited scientific works. Visualizing latent domain knowledge presents a significant challenge to knowledge discovery and quantitative studies of science. We build upon a citation-based knowledge visualization procedure and develop an approach that not only captures knowledge structures from prominent and highly cited works, but also traces latent domain knowledge through low-frequency citation chains. We apply this approach to two cases: (1) identifying cross-domain applications of Pathfinder networks (PFNETs) and (2) clarifying the current status of scientific inquiry of a possible link between Bovine spongiform encephalopathy (BSE), also known as mad cow disease, and a new variant Creutzfeldt-Jakob disease (vCJD), a type of brain disease in humans.