Archives: JUS

Welcome to the fourth issue of the Journal of Usability Studies. In this issue: Most of the articles in this issue have a global flavor addressing issues of international, cross-cultural aspects of usability. The invited essay is written by Elizabeth Rosenzweig who leads the UPA international initiative of the World Usability Day. In her essay “World Usability Day: A challenge for everyone” she outlines the agenda to change the world, at least when it comes to usability. Considering evaluating the usability of an international web site or product? According to Ravi Vatrapu and Manuel A. Pérez-Quiñones in their article: “Culture and Usability Evaluation: The Effects of Culture in Structured Interviews” make sure you have someone from the target cultures on …

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Abstract Small sample sizes are a fact of life for most usability practitioners. This can lead to serious measurement problems, especially when making binary measurements such as successful task completion rates (p). The computation of confidence intervals helps by establishing the likely boundaries of measurement, but there is still a question of how to compute the best point estimate, especially for extreme outcomes. In this paper, we report the results of investigations of the accuracy of different estimation methods for two hypothetical distributions and one empirical distribution of p. If a practitioner has no expectation about the value of p, then the Laplace method ((x+1)/(n+2)) is the best estimator. If practitioners are reasonably sure that p will range between .5 …

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Abstract IBM was contracted to provide a new Air Defence Command and Control (ADCC) system for the Royal Air Force. The IBM Human Factors (HF) team was responsible for the design of the operations room, workstations and the graphical user interfaces. Because the project was safety-related, IBM had to produce a safety case. One aspect of the safety case was a demonstration of the operational effectiveness of the new system. This paper is an in-depth case study of the user testing that was carried out to demonstrate the effectiveness of the system. Due to time constraints the HF team had to observe five participants working simultaneously. Further, to provide a realistic operational environment, up to twenty-eight operators were required for …

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Abstract A proposed design for the American Society of Clinical Oncology (ASCO) Web site was evaluated against the original design in terms of the ease with which the right starting points for key tasks were located and processed. This report focuses on the eye tracking methodology that accompanied other conventional usability practices used in the evaluation. Twelve ASCO members were asked to complete several search tasks using each design. Performance measures such as click accuracy and time on task were supplemented with eye movements which allowed for an assessment of the processes that led to both the failures and the successes. The report details three task examples in which eye tracking helped diagnose errors and identify the better of the …

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Welcome to the third issue of the Journal of Usability Studies. In this issue: The invited essay and peer-reviewed articles in this issue all address aspects that are not necessarily in the main stream, everyday usability studies. In his invited essay, Charlie Kreitzberg asks “Can collaboration help redefine usability?” whereby collaboration refers to having a common, dynamically evolving domain knowledge space. Charlie’s thesis is that a collaborative space like this will not only provide access to an integrated knowledge base of research and practice but also help re-define usability in a more dynamic, collaborative fashion. Agnieszka (Aga) Bojko introduces us to the benefits of using eye movement metrics to compare between user interfaces and assess usability. In her paper “Using …

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