Erik Nilsen

PERCEPTUAL-MOTOR CONTROL IN HUMAN-COMPUTER INTERACTION

Information-oriented jobs are particularly well suited for persons with disabilities, requiring far less physical capability than many other jobs. However, computers themselves may present barriers to workers with physical limitations through poorly designed features and poorly selected adaptive aids. Current methods of input device selection for users with disabilities are unsystematic and rarely result in the selection of a device which allows maximum productivity of the user.

Device comparisons for goal-directed drawing tasks

This study compares five input devices (mouse, mousepen, traekball, stylus, and touchscreen) on a series of goal-directed tasks using a drawing program. Striking performance differences are found for the touchsereen when compared with a previous study using a standard, isolated, laboratory task. The study also looks at the impact of device to screen mapping (absolute vs. relative) and device orientation (horizontal vs. vertical). Performance and preference data point towards an advantage for horizontal relative input devim.

Optimizing speed and accuracy of menu selection: a comparison of walking and pull-down menus

This paper reports three experiments that investigated factors which affect movement time and accuracy of menu selection with a mouse. The experiments primarily focused on the movements required to select from walking menus. The results suggest that width of the path that the cursor must travel can be an important variable in explaining speed and accuracy of motor movement in a walking menu. The studies also investigated the effects of impermeable borders and the size of menu items on movement time. The results show that borders and changing the size of menu items can improve the speed and accuracy of selection time. A final study found that when borders are used on a pull-down bar menu, the time required to access a second-level menu is less than that required by a walking menu, even though the walking menu pops up at the pointer location and the bar menu is located 15 cm away from the initial pointer position.

The growth of software skill: a longitudinal look at learning & performance

This research follows a group of users over time (16 months) as they progress from novice towards expert in their use of Lotus 1-2-3. Quantitative and qualitative measures of performance are compared with expert users having over three years of experience. The results indicate that the motor aspects of performance are relatively stable over time, while improvement in the cognitive components of the skill are dependent on aspects of the menu structure and how many things must be retrieved from memory, among other things. These results imply extensions to the Keystroke Level Model of skilled performance as well as suggest ways to design the user interfaces so as to speed the acquisition of expertise.

Studying the movement of high-tech Rodentia: pointing and dragging

This study compares seven input devices (mouse, touchsereen, two trackba.lls, mousepen,touchp@ and joystick) performing a star tracing task. Along with the device comparisons, the diffemtce between moving with the selector button pressed (dragging) or with the button released (pointing) is examined. Recent work has found that dragging is slower and more error prone than pointing when using a mouse, stylus or trackball [1~,3]. In the present study, 28 subjects used all seven input deviees for boti dragging and pointing tasks. Highly significant device differences were found for both speedand accuracy (p’s <.001). The touchscreen and mouse WE the ~t devius and the joystick and touchpad were the worst. The fastest devices also produced the fewest errors. l%e main effect for the button position was also significant @’s c.005) with dragging being slower and more error-prone than pointing. However, there was a significant interaction between input device and button position. For one of the devices, the mousepen, dragging was actually faster and less error prone than pointing. What is different about the mousepen? Some possibilities are considered along with how these results can be applied to the design of input devices and interaction techniques.

Teaching Cybersecurity Analysis Skills in the Cloud

This paper reports on the experience of using the EDURange framework, a cloud-based resource for hosting on-demand interactive cybersecurity scenarios. Our framework is designed especially for the needs of teaching faculty. The scenarios we have implemented each are designed specifically to nurture the development of analysis skills in students as a complement to both theoretical security concepts and specific software tools. Our infrastructure has two features that make it unique compared to other cybersecurity educational frameworks. First, EDURange is scalable because it is hosted on a commercial, large-scale cloud environment. Second, EDURange supplies instructors with the ability to dynamically change the parameters and characteristics of exercises so they can be replayed and adapted to multiple classes. Our framework has been used successfully in classes and workshops for students and faculty. We present our experiences building the system, testing it, and using feedback from surveys to improve the system and boost user interest.

IRELAND: GENDER, PSYCHOLOGICAL HEALTH, AND ATTITUDES TOWARD EMIGRATION

Ireland is experiencing one of the highest periods of emigration in its history. The current study collected demographic and psychological data on 203 Irish men and women in Ireland and in Northern Ireland, including measures of self-esteem, depression, attitudes toward immigration, and expectancies of emigration. Analysis indicated that approximately 81% of this Irish sample are considering emigration; however, the prospect of emigration is psychologically experienced differently by men and women. While there were no significant differences over-all in scores on self-esteem between Irish men and women, men who contemplated emigration reported higher self-esteem scores, and women contemplating emigration reported lower self-esteem scores (relative to those who had no plans to emigrate). In addition, women who contemplated emigration had higher depression scores than women who did not contemplate emigration. This pattern was not evident for men. These results indicate that psychologically women view the prospect of emigration less positively than men.

Method engineering: from data to model to practice

This paper explores the behavior of experts choosing among various methods to accomplish tasks. Given the results showing that methods are not chosen solely on the basis of keystroke efficiency, we recommend a technique to help designers assess whether they should offer multiple methods for some tasks, and if they should, how to make them so that they are chosen appropriately.

Exploring the divide between two unified theories of cognition: modeling visual attention in menu selection

Two cognitive modeling efforts (EPIC & ACT-R) have proposed computational models of a simple menu selection task involving searching for a single digit in an unordered, pull down menu. This paper presents an empirical study which extends the menu selection task in two dimensions (distance between menu items and whether the items are digits or words). Each of these manipulations should make a difference in selection time according to one of the models but not the other. An analysis of response times reveals that both factors produce significant differences in the direction predicted by the cognitive models. The magnitude of these differences, however, are smaller than predicted (7% for distance and only 3% for word vs. digit). Implications for future modeling of visual attention is briefly addressed.

Reducing visual stress symptoms of VDT users with prescription eyeglasses

The use of Video Display Terminals (VDT’S) in modem information processing environments is associated with a variety of visual stress symptoms including eye strain, headaches, blurry vision and necldshoukler pain. This study evaluates a method of prescribing computer specillc glasses to improve vision and reduce symptoms. Thirty-seven computer users who suffer from VDT related visual symptoms wore two pairs of prescription eyeglasses for two weeks each in a double blind crossover experiment. The experimental glasses were prescribed using a Gaussian image testing device and the control glasses were prescribed using a standard paper Snellen chart. Data was collected on the frequency and severity of symptoms in their regular work environment as well as in a controlled laboratory setting. Results indicate that the experimental eyeglasses were preferred overall (p<.05). Visual stress symptoms were significantly reduced in frequency and severity for the eyeglasses prescribed using the Gaussian image testing device.