Martina Ziefle

Effects of Display Resolution on Visual Performance

The role of display resolution in visual information processing was investigated in 2 experiments. Experiment 1 examined the effects of 2 CRT conditions (resolutions of 60 and 120 dots per inch [dpi]) and a paper control condition (255 dpi) on proofreading speed and accuracy. The results showed that reading performance was significantly better in the paper condition than in the 2 CRT conditions. Experiment 2 examined the effects of 3 different CRT resolutions (62, 69, and 89 dpi) on eye movement parameters (fixation duration and number of fixations) in a visual search task. Further, search reaction times (RTs) and observers′ ratings of visual fatigue were analyzed. RTs and fixation durations were significantly increased in the low-resolution condition (62 dpi) as compared with the high-resolution condition (89 dpi). The significant interaction between display resolution and time both for search RTs and fixation durations was taken as evidence for stronger fatigue in the low-resolution conditions. Additionally, the extent of visual fatigue correlates both with search RTs and eye movement parameters. This finding gives rise to the assumption that observers′ responsiveness to effects of display resolution in terms of visual fatigue differs markedly. Actual or potential applications of this research include recommendations for the use of high-resolution displays (90 dpi and greater) to optimize visual performance, to make prolonged on-screen viewing more comfortable, and to avoid visual fatigue.

The influence of user expertise and phone complexity on performance, ease of use and learnability of different mobile phones

The study focuses on usability, ease of use and learnability of three different mobile phones (Nokia 3210, Siemens C35i, Motorola P7389). The first independent variable refers to the complexity of the menu (depth/breadth of the menu tree) and navigation keys (number/functionality). The Nokia phone had the lowest and the Motorola the highest complexity, with the Siemens phone ranging between them. The second independent variable was user expertise: 30 novices and 30 experts solved six telephone tasks. In order to assess effects of learnability, tasks were presented twice. Differences between the mobile phones regarding effectiveness, efficiency and learnability were found: The best performance was shown by Nokia users. The remaining two phones did not differ significantly, although the most complex phone was superior to the phone of medium complexity which had the lowest performance. Moreover, an effect of expertise was confirmed, though suboptimal interfaces were identified as lessening the advantage of expertise. Specific weaknesses of the tested phones are discussed.

Mental Models of a Cellular Phone Menu. Comparing Older and Younger Novice Users

The interrelationship between mental models of a cellular phone menu and performance depending on users’ age was under study. The mental representation was assessed through card-sorting technique in 32 novice users (16 aged 20-32, 16 50-64 years). First, they had to process four common tasks on two simulated mobiles enabling online logging of users’ actions. None of the older participants had a correct mental representation of the route to be taken to solve a task, and some were not even aware of the hierarchical nature of the phone menu. Younger participants, in contrast, had a fairly correct mental model. Furthermore, it was shown that the better the mental map of the menu, the better the performance using the device. In conclusion, the awareness of the hierarchical structure of the menu is of central importance to use a cellular phone properly. Therefore, it should be made more transparent to the user.

Different Perspectives on Technology Acceptance: The Role of Technology Type and Age

Although eHealth technologies offer an enormous potential to improve healthcare, the knowledge about key determinants of acceptance for eHealth technology is restricted. While the underlying technology of eHealth technologies and Information and Communication technology (ICT) is quite similar, utilization contexts and using motives are quite different. In order to explore the role of technology type on acceptance, we contrasted central application characteristics of both technology types using the scenario technique. A questionnaire was administered (n = 104) measuring individual variables (age, gender) and attitudes regarding an eHealth application (blood sugar meter) in contrast to an ICT device (Personal Digital Assistant, PDA). Older users basically approved the utilization of health-related technologies and perceived lower usability barriers. In addition, we identified main utilization motives of eHealth technology and technology-specific acceptance patterns, especially regarding issues of data safety in the eHealth context. Effects of age and gender in acceptance ratings suggest a differential perspective on eHealth acceptance. Finally, practical interventions were derived in order to support eHealth device design and to promote acceptance of eHealth technology.

Privacy and data security in E-health: requirements from the user's perspective.

In this study two currently relevant aspects of using medical assistive technologies were addressed—security and privacy. In a two-step empirical approach that used focus groups (n = 19) and a survey (n = 104), users’ requirements for the use of medical technologies were collected and evaluated. Specifically, we focused on the perceived importance of data security and privacy issues. Outcomes showed that both security and privacy aspects play an important role in the successful adoption of medical assistive technologies in the home environment. In particular, analysis of data with respect to gender, health-status and age (young, middle-aged and old users) revealed that females and healthy adults require, and insist on, the highest security and privacy standards compared with males and the ailing elderly.

Smart Home Technologies: Insights into Generation-Specific Acceptance Motives

In this research we examine the generation specific acceptance motives of eHealth technologies in order to assess the likelihood of success for these new technologies. 280 participants (14 - 92 years of age) volunteered to participate in a survey, in which using motives and barriers toward smart home technologies were explored. The scenario envisaged was the use of a medical stent implemented into the body, which monitors automatically the health status and which is able to remotely communicate with the doctor. Participants were asked to evaluate the pros and cons of the usage of this technology, their acceptance motives and potential utilization barriers. In order to understand the complex nature of acceptance, personal variables (age, technical expertise, health status), individuals cognitive concepts toward ageing as well as perceived usefulness were related. Outcomes show that trust, believe in the reliability of technology, privacy and security as well as intimacy facets are essential for acceptance and should be considered in order to proactively design a successful rollout of smart home technologies.

Information presentation in small screen devices: The trade-off between visual density and menu foresight

Small mobile devices are ubiquitous and must be designed with great care. One of the most serious challenges is how information on the small displays is presented optimally. This paper addresses the special problem of the increasing number of aged users. On the one hand, information displayed should be easily readable. This requires a low information density and a sufficiently large font size. On the other hand menu orientation is facilitated when the amount of information per screen is maximized and a large preview is allowed. This requires presenting as many functions as possible on the screen at a time. Thus, the tradeoff between readability and orientation demands is crucial. In the present study, this tradeoff was experimentally investigated. Two factors, font size (8pt, 12pt) and the size of the preview (one or five functions per screen at a time) were varied and effects on navigation performance were observed. Forty older participants solved nine common phone navigation tasks twice consecutively on a simulated mobile phone. Both factors contributed to performance, but there was a significant interaction: navigation performance was optimal when font size and the size of the preview were large. The lowest performance was obtained when the preview was small and the font size large, showing that proper orientation is more important than visibility demands. The results can be used in ergonomic guidelines to optimized information presentation on small screens.

From cloud computing to mobile Internet, from user focus to culture and hedonism: The crucible of mobile health care and Wellness applications

With the rise of mobile Internet and cloud computing new ubiquitous medical services will emerge coinciding with changes in demographics and social structures. Mobile e-health and Wellness applications can help relieving the burden of accelerating health care costs due to aging societies. In order to leverage these new innovations a holistic approach must be considered. Facilitating user centered design, acceptance models for user diversity and cultural as well as hedonic aspects can lead to development of services that improve therapy compliance and can even change the youths lifestyle. An overview of such applications is presented and put into a cultural context.

Barriers of information access in small screen device applications: the relevance of user characteristics for a transgenerational design

The proliferation of ubiquitous computing is accompanied by the development of devices, which promise to facilitate the daily living activities of people. However, the question if mobile devices address the usability demands of older users is still unsettled. This paper reports the findings of a series of studies that examined the performance of younger and older adults when using personal data management software applications of a PDA. In order to learn about the ageing impact, the influence of user characteristics like spatial and memory abilities, the subjective technical confidence and computer-expertise on performance outcomes were analysed. Beyond quantitative performance measurements, the major shortcomings in interface design were identified. Results showed that older users reached lower performance outcomes. Even young adults did not reach a perfect performance level, hinting again at shortcomings in the design of PDA applications. Overall, the findings demonstrate the need to include user characteristics in interface design.

Chances of increasing youth health awareness through mobile wellness applications

The poor general state of health of the Austrian youth - which is possibly representative for the western industrial world - will have dramatic effects on our health care system in years to come. Health risks among adolescents, including smoking, alcohol, obesity, lack of physical activity and an unhealthy diet, will lead to an increase in chronic diseases. A preventive measure against such a development could be to reinforce health awareness through the use of web and mobile applications supporting self observation and behavior change. In this paper, we present an overview of the latest developments in the area of mobile wellness and take a look at the features of applications that constitutes the current state of the art, as well as their shortcomings and ways of overcoming these. Finally, we discuss the possibilities offered by new technological developments in the area of mobile devices and by incorporating the characteristics that make up the Web 2.0.