Proceedings of the Human Factors and Ergonomics Society Annual Meeting

Simulated keyboards on touch screens are becoming the norm for data entry on mobile and kiosk systems. Since onscreen keyboards compete with other user interface elements for limited screen space, it is essential that soft keyboard designs are optimally laid out. This paper describes an experiment in which the performance and accuracy of data input on soft keyboards with square keys of two different widths (10 and 15mm) and two inter-key gap distances (1.5 and 4.5mm) were evaluated. Three methods of input were studied: finger, stylus, and trackball. Entry times were the shortest and most accurate for stylus touch, although trackball input was the most accurate for the smallest key size. The spacing between keys did not exhibit a significant effect regardless of key size and input method. A key size of 15mm appears to be sufficiently large to provide acceptable accuracy for touch input, although a key size of 10mm was equally acceptable for trackball input.

Current authentication strategies seek to increase security by requiring users to create more secure alphanumeric passwords. Unfortunately, the inverse relationship between alphanumeric password security and memorability prevents users from being able to create a password that is both secure and memorable. Graphical user authentication mechanisms have been explored as a means to maintain security while enhancing memorability of passcodes. Current approaches often use unrelated picture sets from which participants have to remember a subset, with mixed results. The study outlined in this paper seeks to further validate the Composite Scene Authentication (CSA) graphical passcode mechanism (Johnson & Werner, 2006). Extending retention intervals and increasing the variability of stimuli clearly demonstrated the superiority of CSA over alphanumerical passwords. In addition, we manipulated the mode of presentation (serial vs. composite) to assess the memorability of stimuli presented in different temporal formats. In the current study CSA passcodes consisting of nine categorical dimensions were compared to nine character alphanumeric passwords. Participants showed a strong advantage in passcode retention of graphical passcodes for both modes of presentation. This effect grew larger with increasing retention intervals. At the longest retention interval (6 weeks), only 10 (12%) participants were able to produce their alphanumerical password vs. 50 (60%) participants who were still able to produce the correct graphical passcode.

Movement kinematics has been shown useful for characterizing the process of aiming movement in target acquisition tasks. There are multiple kinematic measures reported in the literature, but their relationship to eventual performance is not well documented. To determine the relationship between various kinematic measures and movement performance, data were collected from participants aged 21 to 90 years with a wide range of psychomotor ability. When computed across age groups, time to peak velocity (TPV), time to peak acceleration (TPA), and time from peak velocity until the end of movement (TPVEND) were found to correlate with movement performance. However, the relationships diminished when the correlations were computed within age groups (except for TPVEND). More interestingly, despite the extensive report, certain kinematic measures such as peak velocity were found to be uncorrelated with performance. Thus, when performance is the focus, improvement should be made to reduce TPV, TPA, and TPVEND.

Gravity mouse is a mouse interface that accelerates the cursor towards potential targets. Its design is based on the premise that as the cursor approaches a potential selection the system can be more certain of the selection. Usability studies with multiple buttons, target and distracter buttons, demonstrate a 100 ms reduction in selection time for 52×41 px buttons and a 130 ms reduction for 19×15 px buttons. Analysis of the results suggests that users resist the full benefit of gravity mouse. Gravity mouse's influence is adaptive and the paper discusses its potential application in intelligent user interfaces.

Two experiments examined the effect of a wide, deep, or balanced telephone menu on task accuracy, task completion time, and user attitude. The wide menu had 8 choices at 2 levels, the deep menu had 2 choices at 6 levels, and the balanced menu had 4 choices at 3 levels. Experiment 1 results indicated no effect of menu structure on task accuracy. Experiment 2 results indicated longer task completion time for the deep menu as compared to the wide and balanced menus. Variability among task completion time for the wide menu, however, indicated an advantage for the balanced menu. User attitude did not vary with the menu structure, but was related to the number of calls needed to complete the tasks, such that the more calls that were needed, the more negatively the telephone menu was viewed.

Executive dashboards have become popular in enterprise software applications. Consequently, much advice has been offered by private consulting firms on how best to design dashboards. This paper details a couple of studies testing the advice given by the dashboard experts. The results suggest that some of the notions about how dashboard widgets should be designed might be incorrect. The results indicate that colored widgets are not necessarily inferior to simpler, colorless widgets. Similarly, fancy widgets (i.e., those with three dimensional characteristics) were not demonstrated to be inferior to plainer widgets. While some methodological challenges must be overcome in similar future studies, the results of the described studies do not support some popular ideas about executive dashboards (and data visualization in general), and suggest that the area of interest is ripe for further investigation.

A concept map is a diagram that consists of nodes that contain individual concepts or pieces of information. These nodes are connected by lines that represent relationships between the information. Large concept maps are difficult to explore and navigate using current digital display interfaces. As users zoom in on a desired node, connections between the node of interest and surrounding nodes become hidden from the user. A combination of fisheye zooming and semantic zooming mechanisms to maintain the visual connections between the nodes was implemented, and a user study to determine whether this technique helps users learn from the map was conducted. The user study revealed that participants were able to recall more information presented in a concept map, with practically no difference in the amount of time spent using the map, despite the novelty of the semantic fisheye interface.

This study investigated the effect that typeface has on a reader's perception of three different types of onscreen documents (business, email, and youth narrative stories). Participants read documents displayed in either a congruent, neutral, or incongruent typeface. Results suggest that the less congruent the typeface, the more the document was perceived in a negative fashion. That is, the typeface itself affected the perceived personality of the document and the perception of the author; thus, typeface appropriateness should be considered when writing an onscreen document.

With the ROI of persona methods still being arguable, it is important to understand how personas can be utilized in user interface design. The extensive methods proposed by Pruitt and Adlin (2006), throw light on several ways to use persona methods in user interface design lifecycle and also propose mitigations to several risk factors that can be encountered in this process. However, there is very little research presenting case studies on an entire design lifecycle that utilizes personas. This paper presents design, development and evaluation of a web-based audit management system in aircraft maintenance domain with emphasis on the persona creation process, the design approach followed, and the user testing results obtained. The experiences of a design team novice to personas will be discussed.

Many studies of usability studies count the number of usability problems identified to measure the effectiveness of an evaluation. However, communicating problems is also important to evaluation effectiveness, because a problem found but poorly explained may not be fixed. This study compared lists of usability problems from 21 practitioners and 23 students watching a pre-recorded usability session. Lists were evaluated for the number of problems reported, and for following six guidelines for describing usability problems: be clear and avoid jargon, describe problem severity, provide backing data, describe problem causes, describe user actions, and provide a solution. There was no difference in the number of problems reported by students and practitioners, but there was a difference in their ratings for following several of the guidelines. Using both measures provides a more complete assessment of usability reports.

This paper describes results of a study of high school juniors and seniors who participated in their school's 24/7 access tablet PC (TPC) program during the program's third year. Primary areas of interest for this study were students' experiences with and attitudes about the TPCs, physical discomfort associated with TPC use, and temporal and task-driven patterns of TPC use. Data were collected via questionnaire. Results showed students' attitudes were generally quite positive towards the TPCs. However, they did not tend to think TPCs had improved their grades, few disagreed that TPCs were a distraction in class, and visual and musculoskeletal discomfort was prevalent. Recognizing the organizational capacity of the TPC was associated with several positive attitudes towards the TPC, including aiding interactions with teachers and feeling more comfortable in class. This type of assessment provides a useful complement to more common assessments of impact of digital technology on academic performance.

Self-service modules have become an integral part of the economy throughout the world, replacing expensive human operators in many settings. However, usability issues continue to diminish the economic value of these modules. This experiment demonstrates how the application of sound usability principles can be applied to self-service settings to increase the usability of self-service modules. The study compared the usability of two versions of a self-service digital photo kiosk. In one version we replicated a kiosk presently in use and broadly available. The other version of the software incorporated several design principles, such as the use of a metaphor, intended to increase usability and learnability, more specifically to allow for easier navigation. Participant's performance in completing tasks was measured as a function of speed, accuracy, and the need for human assistance. The results demonstrate that incorporating usability principles can improve usability of self-service modules.

Remote navigation, popular in computer games and prevalent in areas such as clinical medicine and teleoperations of robots and drones, uses human-computer interfaces for control. Usability studies of remote navigation interfaces require good metrics for evaluating interfaces, assessing users' capabilities, and determining the difficulty of the navigational task. We studied the time proficient users took to navigate virtual hovercrafts through virtual hallways with corners of various widths and discovered that the time to negotiate corners is inversely proportional to corner width. We derive and evaluate two models for the index of difficulty for negotiating corners. Both models fit the data well, with r² greater than 0.85 for the mean time to negotiate corners verses corner width.