S. Camille Peres

Hidden Costs of Graphical User Interfaces: Failure to Make the Transition from Menus and Icon Toolbars to Keyboard Shortcuts

Graphical interfaces allow users to issue commands using pull-down menus, icon toolbars, and keyboard shortcuts. Menus and icon toolbars are easier to learn, whereas keyboard shortcuts are more efficient. It would seem natural for users to migrate from the use of easy-to-learn menu and icon methods to the more efficient method of keyboard shortcuts as they gain experience. To investigate the extent to which this transition takes place, 251 experienced users of Microsoft Word were given a questionnaire assessing their choice of methods for the most frequently occurring commands. Contrary to our expectations, most experienced users rarely used the efficient keyboard shortcuts, favoring the use of icon toolbars instead. A second study was done to verify that keyboard shortcuts are, indeed, the most efficient method. Six participants performed common commands using menu selection, icon toolbars, and keyboard shortcuts. The keyboard shortcuts were, as expected, the most efficient. These studies show that even experienced users are inefficient in their use of graphical interfaces. One possible way to improve user efficiency is for training programs to provide a roadmap for users to make the transition from using pull-down menus and clicking icon toolbars to issuing keyboard shortcuts.

The Relationship Between System Effectiveness and Subjective Usability Scores Using the System Usability Scale

This article examines the relationship between users’ subjective usability assessments, as measured using the System Usability Scale (SUS), and the ISO metric of effectiveness, using task success as the measure. The article reports the results of two studies designed to explore the relationship between SUS scores and user success rates for a variety of interfaces. The first study was a field study, where stereotypical usability assessments on a variety of products and services were performed. The second study was a well-controlled laboratory study where the level of success that users were able to achieve was controlled. For both studies, the relationship between SUS scores and their attendant performance were examined at both the individual level and the average system level. Although the correlations are far from perfect, there are reliable and reasonably strong positive correlations between subjective usability measures and task success rates, for both the laboratory and field studies at both the individual and system level.

Validation of the System Usability Scale (SUS) SUS in the Wild

For almost 20 years, practitioners and researchers have been using the System Usability Scale (SUS) as a “quick and dirty” method of evaluating the usability of different websites, software, and other human-machine systems. The characteristics of the SUS (e.g., reliability, number of scales, etc.) have been widely discussed in the literature but there have been little written about how the results of the SUS relate to traditional usability results (likely due primarily to these results being proprietary). In this study, eight different usability studies were used to make a direct comparison between the SUS and usability results. A significant but small relation was found between these two scores suggesting that the SUS may be a valid measure to ordinally compare two or more systems.

The System Usability Scale Beyond Standard Usability Testing

The system usability scale (SUS; Brooke, 1996) is an instrument commonly utilized in usability testing of commercial products. The goal of this symposium is to discuss the validity of the SUS in usability tests and beyond. This article serves as an introduction to the symposium. Specifically, it provides an overview of the SUS and discusses research questions currently being pursued by the panelists. This current research includes: defining usability norms, assessing usability without performing tasks, and the use of SUS for ergonomics. In addition to this paper, there are four other papers in the symposium, which discuss the impact of experience on SUS data, the relationship between SUS and performance scores, the linkage between SUS and business metrics, as well as the potential for using SUS in test and evaluation for military systems.

Call Center Productivity Over 6 Months Following a Standing Desk Intervention

OCCUPATIONAL ABSTRACT Stand-capable desks have been shown to successfully reduce sedentary behavior in the modern office, but whether their utilization improves cognitive productivity is not known. We compared productivity between stand-capable desk users and traditional seated desk users in a call center environment. Data were collected daily over a continuous 6-month period. We found that increased stand-capable desk use is a likely contributor to increased productivity over traditional seated desk use. These findings indicate that use of stand-capable desks as ergonomic interventions to improve physical health among employees may also positively impact their work productivity. TECHNICAL ABSTRACT Background: Many office employees are spending up to 90% of their workday seated, and employers are considering stand-capable desks as a way to increase physical activity throughout the day. When deciding on adoption of stand-capable workstations, a major concern for employers is that the benefits, over time, may not offset the initial cost of implementation. Methods: This study compared objective measures of productivity over time between a group of stand-capable desk users and a seated control group in a call center. Comparison analysis was completed for continuous 6-month secondary data for 167 employees, across two job categories. Results: Users of stand-capable desks were ∼45% more productive on a daily basis compared to their seated counterparts. Further, productivity of the stand-capable desk users significantly increased over time, from ∼23% in the 1st month to ∼53% over the next 6 months. Finally, this productivity increase was similar for employees across both job categories. Conclusions: These findings suggest important benefits of employing stand-capable desks in the work force to increase productivity. Prospective studies that include employee health status, perceptions of (dis)comfort and preference over time, along with productivity metrics, are needed to test the effectiveness of stand-capable desks on employee health and performance.

Differences in Muscle Activity for 4 Touch Devices

The use of touch devices has become pervasive in businesses, coffee shops, homes, and schools. These devices are used for a myriad of different tasks for extended periods of time. However, there is little known about the effects on user’s muscles when these devices are used for extended periods of time. As part of a larger project, we present here results about the differing levels of muscle exertion degree of dynamic activity for muscles when people use four different touch devices—an iPod touch, iPad, touch screen desktop and a touch screen laptop. Participants completed four separate tasks with the devices and there were surprising and interesting differences found by device for the different muscles and tasks.

Examining User Preferences in Interacting with Touchscreen Devices

The introduction of touchscreen technology has remarkably changed how people interact with their devices. Users may adopt different methods of input depending on the type of device they are interacting with and the type of task being performed. In the present study, we collected data on users’ preferences with regards to interface interaction, device position, and posture, while performing various tasks with four different touch screen devices: a touchscreen desktop, laptop, iPad or iPod Touch. Results indicated that users prefer touch over traditional input devices when performing more interactive tasks (ex: drawing, gaming). We also observed that the device position adopted by users may promote suboptimal flexion angles of the torso, neck and wrists. The information gleaned from this study contributes to the limited body of knowledge on the ergonomic implications of touch screen devices.

An Exploration of the use of Complete Songs as Auditory Progress Bars

This paper examines the results of a study conducted to determine if Auditory Progress Bars consisting of complete songs of varying duration would allow listeners to accurately estimate the amount of time they were on telephone hold, while at the same time producing acceptable customer satisfactions scores. Previous research by the authors has shown that a subset of auditory progress bars consisting of sinusoidal wave forms in different configurations do indeed allow listeners to accurately estimate time, while other configurations did not. However, this research also showed that all of the tonal auditory progress bars had exceptionally low customer satisfaction scores. The current research demonstrates that auditory progress bars comprised of complete songs produce both accurate hold time estimates and high consumer satisfaction scores. Implications for the design of auditory progress bars and directions for further research are discussed.

Evaluation of Home Health Care Devices: Remote Usability Assessment

Background An increasing amount of health care is now performed in a home setting, away from the hospital. While there is growing anecdotal evidence about the difficulty patients and caregivers have using increasingly complex health care devices in the home, there has been little systematic scientific study to quantify the global nature of home health care device usability in the field. Research has tended to focus on a handful of devices, making it difficult to gain a broad view of the usability of home-care devices in general. Objective The objective of this paper is to describe a remote usability assessment method using the System Usability Scale (SUS), and to report on the usability of a broad range of health care devices using this metric. Methods A total of 271 participants selected and rated up to 10 home health care devices of their choice using the SUS, which scores usability from 0 (unusable) to 100 (highly usable). Participants rated a total of 455 devices in their own home without an experimenter present. Results Usability scores ranged from 98 (oxygen masks) to 59 (home hormone test kits). An analysis conducted on devices that had at least 10 ratings showed that the effect of device on SUS scores was significant (P<.001), and that the usability of these devices was on the low end when compared with other commonly used items in the home, such as microwave ovens and telephones. Conclusions A large database of usability scores for home health care devices collected using this remote methodology would be beneficial for physicians, patients, and their caregivers.

Software ergonomics: relating subjective and objective measures

The use of computers in the workplace is now commonplace. Correspondingly, injuries associated with computer use have increased. However, little research has been done investigating whether these injuries are associated with the software being used. One reason is the difficulty in measuring muscle strain (a predictor of muscle related injuries). Here we present preliminary results of study on the relationship between objective and subjective measures of muscle strain during computer use. As users completed sets of tasks using MSWord®, SEMG muscle activity was recorded for the muscles associated with using a keyboard and mouse. After each task set, users completed surveys asking the level of strain they experienced during the tasks. Correlations between the measures suggest that subjective measures can provide reliable information regarding the muscle strain associated with software use. These easily obtained subjective measurements could assist in producing software interaction designs that are better for users.