Touch a screen or turn a knob: choosing the best device for the job

Touch or click friendly: Towards adaptive user interfaces for complex applications

This study evaluated the usability of a direct manipulation device (touchscreen) vs. indirect manipulation devices (mouse and touchpad) on the selected Microsoft (MS) Word tasks as per ISO-9241-11 standard. MS Word was taken as an example of a complex application. The tasks were evaluated in terms of touch-friendly or click-friendly using efficiency, effectiveness, and satisfaction parameters to propose a customized task menu. The experiment was conducted with fifty-four participants, divided into three MS Word usage-based expertise groups. Each participant performed fifty-six tasks using a mouse, a touchpad, and a touchscreen. To assess task-level usability, individual one-way ANOVAs were performed for each task to gauge both efficiency and effectiveness. It's worth noting that the touchscreen significantly outperformed other input methods in just one specific task regarding effectiveness. Consequently, an ANCOVA was employed, with task completion time as the independent variable and the number of errors as a covariate, to further investigate effectiveness. A total of 19 (34%) of the total tasks were found to be significantly efficient with a mouse, while 21 (37.5%) were significantly efficient with a touchscreen. Based on the results, a customized menu is recommended for MS Word-like applications that combine actions in touch-friendly tasks and mouse-friendly tasks separately.

Fitts' law on the flight deck: evaluating touchscreens for aircraft tasks in actual flight scenarios

This research investigated the effects of an abnormal flight environment using touch-based navigation displays (TNDs). Fitts' law was used to compare the performance of TNDs with control display units (CDUs) and mode control panel (MCPs) under three different flight scenarios (normal, turbulence and startled). A within-subjects design involving 15 male participants was used. Data were collected in respect to accuracy, movement time, subjective feelings, choices and comments. The results showed that under abnormal conditions, TNDs showed worse operation performance and stability than CDUs and MCPs; however, it was easy to learn from TNDs, and they provided a good user experience. Moreover, this research demonstrated the application of Fitts' law to describe pilot behaviours in interactive flight devices, particularly for tasks involving real flight operations. TND designs for aviation could be developed based on these findings to improve flight crew performance when using new technology.Practitioner summary: This research built a Fitts' law model to evaluate the performance of aircraft cockpit touchscreens under normal, turbulence and startled scenarios. We compared the different touchscreens (TNDs) with other traditional interactive devices, such as CDUs and MCPs. The results have implications for the design of aircraft cockpit touchscreens and define the task scenario. Furthermore, the results contribute to the development of scenes utilising Fitts' law.

Development of the Mental Number Line Representation of Numbers 0–10 and Its Relationship to Mental Arithmetic

The internal representation of numbers on the mental number line (MNL) was demonstrated by performing the computerized version of the number-to-position (CNP) task on a touchscreen while restricting response time. We found that the estimation pattern is best fit by a sigmoid function, further denoted as the “sigmoidal model”. Two developmental leaps occurring during elementary school were recognized: (1) the division of the number line into two segments and (2) consistent use of different anchor points on the number line—the left endpoint in first grade, the right endpoint in second grade, and finally the midpoint in third grade. Additionally, when examining the differences between the breakpoints, we found that first graders demonstrated a breakpoint close to 6, which linearly decreased over the years until stabilizing close to 5. The relation between the ability to place individual numbers on a number line and performance of mental arithmetic showed that the consistent use of anchor points correlated significantly with faster responses in mental arithmetic.

A Comparison of Touchscreen and Mouse for Real-World and Abstract Tasks with Older Adults

Computer technology is increasingly being used to facilitate the timely identification of cognitive impairment in older adults. Our Cognitive Testing on Computer (C-TOC) project aims to develop a self-administered online test for older adults to take at their home. Due to the freedom of devices they can use, it is important to investigate whether different input devices can impact test performance. We compared touchscreen and mouse input on both abstract and real-world pointing and dragging tasks: classic Fitts’s Law tasks and tasks drawn from C-TOC. The abstract and real-world tasks were designed to require equivalent motor skills. Our research goals were to determine (1) if performance on computerized cognitive tasks are affected by input device, and (2) if performance differences due to input device can be explained by those observed on Fitts’s Law tasks. Sixteen older adults completed both types of tasks using a touchscreen and a mouse. We found that input device affected speed on three out of four cognitive tasks while only affecting accuracy on one task. Secondarily, our results suggest that Fitts’s Law results of differences in mouse and touch cannot be used to predict device differences in the performance on C-TOC tests. As an additional research goal, we looked into the movement patterns of one real-world dragging task—the C-TOC Pattern Construction task—to see if they could provide richer performance measures, beyond speed and accuracy. Such measures could compensate for the lack of a clinician observer who is typically present in comparable paper-based cognitive tests. We found that older adults naturally adopted different movement patterns on the two devices: they tended to make shorter moves and a greater number of moves on a touchscreen than with a mouse. Altogether, our results suggest that careful device-based performance calibration will be needed in computerized tests.

Touchscreens for Aircraft Navigation Tasks: Comparing Accuracy and Throughput of Three Flight Deck Interfaces Using Fitts' Law

OBJECTIVE

Use Fitts' law to compare accuracy and throughput of three flight deck interfaces for navigation.

BACKGROUND

Industry is proposing touch-based solutions to modernize the flight management system. However, research evaluating touchscreen effectiveness for navigation tasks in terms of accuracy and throughput on the flight deck is lacking.

METHOD

An experiment was conducted with 14 participants in a flight simulator, aimed at creating Fitts' law accuracy and throughput models of three different flight deck interfaces used for navigation: the mode control panel, control display unit, and a touch-based navigation display. The former two constitute the conventional interface between the pilot and the flight management system, and the latter represents the industry-proposed solution for the future.

RESULTS

Results indicate less accurate performance with the touchscreen navigation display compared to the other two interfaces and the throughput was lowest with the mode control panel. The control display unit was better in both accuracy and throughput, which is found to be largely attributed to the tactile and physical nature of the interface.

CONCLUSION

Although performance in terms of accuracy and throughput was better with the control display unit, a question remains whether, when used during a more realistic navigation task, performance is still better compared to a touch-based interface.

APPLICATION

This paper complements previous studies in the usage of aircraft touchscreens with new empirical insights into their accuracy and throughput, compared to conventional flight deck interfaces, using Fitts' law.

Summary of Indiana Farm Fatalities Involving Individuals 55 Years and Older—1988–2017

Agriculture has historically been one of the most hazardous of all occupations, with a variety of potential safety risks to workers and even higher risks documented for older agricultural workers. This study was undertaken to document and summarize Indiana farm work-related fatalities involving persons 55 years and older over the 30 year period from 1988 to 2017. Data were mined from the Purdue University Agricultural Safety and Health Program’s Fatality Database that dates back to the 1960s. A total of 388 fatalities involving persons 55 years and older was documented. The average age of the victims was 69.3 years old, and an overwhelming majority of the cases involved males (96.1%). The average number of deaths per year has remained fairly consistent, though it has occasionally been erratic, with an unanticipated increase in the number of documented fatalities over the period 2012–2017. There appeared to be a direct positive correlation between the level or intensity of agricultural production in a county and the frequency of fatalities. The type of fatal injury most commonly reported was crush/run-over, with 229 cases (59%). The most common agent or source of injury involved was tractors, with 157 cases (40.5%). Another noted contributing factor was the high frequency of incidents in which the victim was reported to be working alone at the time of death. Findings will be used to develop evidence-based injury prevention strategies, including the development of agricultural safety training materials and methods more relevant to older farmers. A special emphasis should be placed on reducing the risk of tractor and farm machinery overturns, especially when older, non-roll over protection structure (ROPS) equipped tractors are being operated.

Effects of Aging on Small Target Selection with Touch Input

Age-related declines in physical and cognitive function can result in target selection difficulties that hinder device operation. Previous studies have detailed the different types of target selection errors encountered, as well as how they vary with age and with input device for mouse and pen interaction. We extend this work to describe the types of age-related selection errors encountered with small touchscreen devices. Consistent with prior results, we found that older adults had longer target selection times, generated higher error rates, and encountered a broader range of selection difficulties (e.g., miss errors and slip errors) relative to a younger comparison group. However, in contrast to the patterns previously found with pen interaction, we found that miss error (i.e., both landing and lifting outside the target bounds) was a more common source of errors for older adults than slip error (i.e., landing on the target but slipping outside the target bounds before lifting). Moreover, aging influenced both miss and slip errors in our study of touch interaction, whereas for pen interaction, age has been found to influence only slip errors. These differences highlight the need to consider pen and touch interaction separately despite both being forms of direct input. Based on our findings, we discuss possible approaches for improving the accessibility of touch interaction for older adults.

Future technology on the flight deck: assessing the use of touchscreens in vibration environments

Use of touchscreens in the flight deck has been steadily increasing, however, their usability may be severely impacted when turbulent conditions arise. Most previous research focusses on using touchscreens in static conditions; therefore, this study assessed touchscreen use whilst undergoing turbulent representative motion, generated using a 6-axis motion simulator. Touchscreens were tested in centre, side and overhead positions, to investigate how turbulence affected: (1) error rate, movement times and accuracy, (2) arm fatigue and discomfort. Two touchscreen technologies were compared: a 15" infra-red and a 17.3" projected capacitive touchscreen with force sensing capability. The potential of the force sensing capability to minimise unintentional interactions was also investigated. Twenty-six participants undertook multi-direction tapping (ISO 9241; ISO 2010 ) and gesture tasks, under four vibration conditions (control, light chop, light turbulence and moderate turbulence). Error rate, movement time and workload increased and usability decreased significantly, with screen position and increasing turbulence level. Practitioner Summary: This study evaluated the use of infra-red and projected capacitive touchscreen technologies using multi-directional tapping and gesture tasks, whilst being subjected to different levels of turbulence representative motion. Performance degraded significantly with increasing turbulence level and touchscreen location. This has implications for future flight deck design.

Attitudes Toward Computers Across Adulthood From 1994 to 2013

Background and Objectives

Regardless of the increased deployment of technologies in everyday living domains, barriers remain that hamper technology adoption by older adults. Understanding barriers to adoption such as individual differences in attitudes toward computers is important to the design of strategies to reduce age-related digital disparities.

Research Design and Methods

This article reports a time-sequential analysis of data from the Edward R. Roybal Center on Human Factors and Aging Research and the Center for Research and Education on Aging and Technology Enhancement (CREATE) on computer attitudes among a large (N = 3,917), diverse sample of community-dwelling adults aged from 18 to 98 years. The data were gathered from 1994 to 2013.

Results

The findings indicated that there are still age disparities in attitudes; older adults report less comfort with and less efficacy about using computers than younger people. We also found a cohort (birth year) effect; attitudes are generally more positive among more recent birth cohorts. Those who have more education and experience with computers also have more positive attitudes. Males generally have more positive attitudes than females; however, the gender difference decreases with increased age.

Discussion and Implications

Technology affords potential benefits for older people, but lack of uptake in technology clearly puts older adults at a disadvantage in terms of negotiating today's digital world. This article provides insight into attitudinal barriers that may affect on technology uptake among older adults. The findings have implications for the design of technology training programs, design of technology systems, and policy.

The Virtual Shop: A new immersive virtual reality environment and scenario for the assessment of everyday memory

BACKGROUND

Assessing and predicting memory performance in everyday life is a common assignment for neuropsychologists. However, most traditional neuropsychological tasks are not conceived to capture everyday memory performance.

NEW METHOD

The Virtual Shop is a fully immersive task developed to assess memory in a more ecological way than traditional neuropsychological assessments. Two studies were undertaken to assess the feasibility of the Virtual Shop and to appraise its ecological and construct validity. In study 1, 20 younger and 19 older adults completed the Virtual Shop task to evaluate its level of difficulty and the way the participants interacted with the VR material. The construct validity was examined with the contrasted-group method, by comparing the performance of younger and older adults. In study 2, 35 individuals with subjective cognitive decline completed the Virtual Shop task. Performance was correlated with an existing questionnaire evaluating everyday memory in order to appraise its ecological validity. To add further support to its construct validity, performance was correlated with traditional episodic memory and executive tasks.

RESULTS

All participants successfully completed the Virtual Shop. The task had an appropriate level of difficulty that helped differentiate younger and older adults, supporting the feasibility and construct validity of the task.

COMPARISON WITH EXISTING METHOD(S)

The performance on the Virtual Shop was significantly and moderately correlated with the performance on the questionnaire and on the traditional memory and executive tasks.

CONCLUSIONS

Results support the feasibility and both the ecological and construct validity of the Virtual Shop.

Technology and Aging

Technological advancements have become widespread, and their implementation into products of everyday use is accelerating. Technology has the potential to improve the lives of older adults by increasing their safety, security, and independence in daily life. However, too often older adults' capabilities and limitations are not considered in the design of current and future technologies. In 1990, the National Research Council identified the importance of human factors in the design of technology for an aging population. The goal of this chapter is to review research on aging and technology since that report to determine the contributions of human factors research to issues of aging and technology design. In this chapter we address the extent to which older adults use new technologies, factors to consider in the adoption of technology (e.g., attitudes), the influence of technology design on older adults' performance (e.g., design of input devices), and ways to optimize training for older adults in using new technologies (e.g., age-specific instructional designs). We then review emerging areas of research that may direct the focus of human factors research in the next decade. These areas of research include ubiquitous computing (e.g., home monitoring systems), health care technologies (e.g., telehealth), robotics (e.g., Nursebot), and automated systems (e.g., cruise control). Finally, we consider opportunities and challenges to human factors research as the field continues to address the questions of optimizing technology for older adult users.

Concepts, Terms, and Mental Models: Everyday Challenges to Older Adult Social Media Adoption

Social connection and social support are strong predictors of wellbeing, but maintaining social relations often becomes more difficult at older ages. Because social media enhance feelings of connectedness and reduce feelings of loneliness, they may present accessible and relatively low cost mechanisms to enhance life quality at older ages. Using data gathered from two focus groups of potential older adult social media learners, we explored the physical and cognitive challenges to social media use, perceptions of social media benefits, and conceptual barriers to use. Findings support earlier studies that identify perceived benefit as important to social media adoption at older ages, and extend these by identifying that a lack in conceptual knowledge of these technologies is an additional barrier to use. We then discuss the cognitive implications of gaining this knowledge.

Evaluating change in user error when using ruggedized handheld devices

The increasing number of handheld mobile devices used today and the increasing dependency on them in the workplace makes understanding how users interact with these devices critical. This study seeks to understand how user error changes based on user age as well as input content type on ruggedized handheld devices. Participants completed data entry tasks of word and character input on two different devices, a physical keypad and touchscreen device. The number of errors and types of error, corrected and permanent were collected for each participant. Based on results on the study, touchscreen devices proved to be the optimal ruggedized handheld device to minimize user error.

Examining the Usability of Touch Screen Gestures for Older and Younger Adults

OBJECTIVE

We examined the usability issues associated with four touch screen gestures (clicking, dragging, zooming, and rotating) among older and younger users.

BACKGROUND

It is especially important to accommodate older users' characteristics to ensure the accessibility of information and services that are important to their quality of life.

METHOD

Forty older and 40 younger participants completed four experiments, each of which focused on one gesture. The effects of age, type of touch screen (surface acoustic wave vs. optical), inclination angle (30°, 45°, 60°, and 75°), and user interface factors (clicking: button size and spacing; dragging: dragging direction and distance; zooming: design of zooming gesture; rotating: design of rotating gesture) on user performance and satisfaction were examined.

RESULTS

Button sizes that are larger than 15.9 × 9.0 mm led to better performance and higher satisfaction. The effect of spacing was significant only when the button size was notably small or large. Rightward and downward dragging were preferred to leftward and upward dragging, respectively. The younger participants favored direct manipulation gestures using multiple fingers, whereas the older participants preferred the click-to design. The older participants working with large inclination angles of 60° to 75° reported a higher level of satisfaction than the older participants working with smaller angles.

CONCLUSION

We proposed a set of design guidelines for touch screen user interfaces and discussed implications for the selection of appropriate technology and the configuration of the workspace.

APPLICATION

The implications are useful for the design of large touch screen applications, such as desktop computers, information kiosks, and health care support systems.

Designing and optimizing a healthcare kiosk for the community

Investigating new ways to deliver care, such as the use of self-service kiosks to collect and monitor signs of wellness, supports healthcare efficiency and inclusivity. Self-service kiosks offer this potential, but there is a need for solutions to meet acceptable standards, e.g. provision of accurate measurements. This study investigates the design and optimization of a prototype healthcare kiosk to collect vital signs measures. The design problem was decomposed, formalized, focused and used to generate multiple solutions. Systematic implementation and evaluation allowed for the optimization of measurement accuracy, first for individuals and then for a population. The optimized solution was tested independently to check the suitability of the methods, and quality of the solution. The process resulted in a reduction of measurement noise and an optimal fit, in terms of the positioning of measurement devices. This guaranteed the accuracy of the solution and provides a general methodology for similar design problems.

Computerized neuropsychological assessment in aging: testing efficacy and clinical ecology of different interfaces

Digital technologies have opened new opportunities for psychological testing, allowing new computerized testing tools to be developed and/or paper and pencil testing tools to be translated to new computerized devices. The question that rises is whether these implementations may introduce some technology-specific effects to be considered in neuropsychological evaluations. Two core aspects have been investigated in this work: the efficacy of tests and the clinical ecology of their administration (the ability to measure real-world test performance), specifically (1) the testing efficacy of a computerized test when response to stimuli is measured using a touch-screen compared to a conventional mouse-control response device; (2) the testing efficacy of a computerized test with respect to different input modalities (visual versus verbal); and (3) the ecology of two computerized assessment modalities (touch-screen and mouse-control), including preference measurements of participants. Our results suggest that (1) touch-screen devices are suitable for administering experimental tasks requiring precise timings for detection, (2) intrinsic nature of neuropsychological tests should always be respected in terms of stimuli presentation when translated to new digitalized environment, and (3) touch-screen devices result in ecological instruments being proposed for the computerized administration of neuropsychological tests with a high level of preference from elderly people.

A comparison of tablet computer and paper-based questionnaires in healthy aging research

Background

Digital questionnaire delivery offers many advantages to investigators and participants alike; however, evidence supporting digital questionnaire delivery via touchscreen device in the older adult population is lacking.

Objective

The objective of this study was to compare the use of tablet computer-delivered and printed questionnaires as vehicles for the collection of psychosocial data from older adults to determine whether this digital platform would be readily adopted by the sample, and to identify whether tablet delivery influences the content of data received.

Methods

The participants completed three questionnaires using both delivery methods, followed by a brief evaluation.

Results

A nonparametric one-sample binomial test indicated a significantly greater proportion of individuals preferred the tablet-delivered questionnaires (z=4.96, SE 3.428, P<.001). Paired sample t tests and Wilcoxon sign-rank tests indicated that measures collected by each method were not significantly different (all P≥.273). Ease of use of the tablet interface and anxiety while completing the digital questionnaires were significantly correlated with preferences, (r_s=.665, P<.001 and r_s=.552, P<.001, respectively). Participants most frequently reported that the tablet delivery increased speed of use and improved data entry, although navigation was perceived as being more difficult. By comparison, participants felt that the paper packet was easier to read and navigate, but was slow and cumbersome, and they disliked the lack of dynamic features.

Conclusions

This study provides preliminary evidence suggesting that questionnaires delivered to older adults using contemporary tablet computers may be acceptable and do not substantively influence the content of the collected data.

Age and gestural differences in the ease of rotating a virtual 3D image on a large, multi-touch screen

Providing a natural mapping between multi-touch gestures and manipulations of digital content is important for user-friendly interfaces. Although there are some guidelines for 2D digital content available in the literature, a guideline for manipulation of 3D content has yet to be developed. In this research, two sets of gestures were developed for experiments in the ease of manipulating 3D content on a touchscreen. As there typically are large differences between age groups in the ease of learning new interfaces, we compared a group of adults with a group of children. Each person carried out three tasks linked to rotating the digital model of a green turtle to inspect major characteristics of its body. Task completion time, subjective evaluations, and gesture changing frequency were measured. Results showed that using the conventional gestures for 2D object rotation was not appropriate in the 3D environment. Gestures that required multiple touch points hampered the real-time visibility of rotational effects on a large screen. While the cumulative effects of 3D rotations became complicated after intensive operations, simpler gestures facilitated the mapping between 2D control movements and 3D content displays. For rotation in Cartesian coordinates, moving one fingertip horizontally or vertically on a 2D touchscreen corresponded to the rotation angles of two axes for 3D content, while the relative movement between two fingertips was used to control the rotation angleof the third axis. Based on behavior analysis, adults and children differed in the diversity of gesture types and in the touch points with respect to the object's contours. Offering a robust mechanism for gestural inputs is necessary for universal control of such a system.

Skill acquisition with text-entry interfaces: particularly older users benefit from minimized information-processing demands

Operating information technology challenges older users if it requires executive control, which generally declines with age. Especially for novel and occasional tasks, cognitive demands can be high. We demonstrate how interface design can reduce cognitive demands by studying skill acquisition with the destination entry interfaces of two customary route guidance systems. Young, middle-aged, and older adults performed manual destination entry either with a system operated with multiple buttons in a dialogue encompassing spelling and list selection, or with a system operated by a single rotary encoder, in which an intelligent speller constrained destination entry to a single line of action. Each participant performed 100 training trials. A retention test after at least 10 weeks encompassed 20 trials. The same task was performed faster, more accurately, and produced much less age-related performance differences especially at the beginning of training if interface design reduced demand for executive control, perceptual processing, and motor control.

To twist, roll, stroke or poke? A study of input devices for menu navigation in the cockpit

Modern interfaces within the aircraft cockpit integrate many flight management system (FMS) functions into a single system. The success of a user's interaction with an interface depends upon the optimisation between the input device, tasks and environment within which the system is used. In this study, four input devices were evaluated using a range of Human Factors methods, in order to assess aspects of usability including task interaction times, error rates, workload, subjective usability and physical discomfort. The performance of the four input devices was compared using a holistic approach and the findings showed that no single input device produced consistently high performance scores across all of the variables evaluated. The touch screen produced the highest number of 'best' scores; however, discomfort ratings for this device were high, suggesting that it is not an ideal solution as both physical and cognitive aspects of performance must be accounted for in design.

PRACTITIONER SUMMARY

This study evaluated four input devices for control of a screen-based flight management system. A holistic approach was used to evaluate both cognitive and physical performance. Performance varied across the dependent variables and between the devices; however, the touch screen produced the largest number of 'best' scores.

Modelling the hare and the tortoise: predicting the range of in-vehicle task times using critical path analysis

Analytic models can enable predictions about important aspects of the usability of in-vehicle information systems (IVIS) to be made at an early stage of the product development process. Task times provide a quantitative measure of user performance and are therefore important in the evaluation of IVIS usability. In this study, critical path analysis (CPA) was used to model IVIS task times in a stationary vehicle, and the technique was extended to produce predictions for slowperson and fastperson performance, as well as average user (middleperson) performance. The CPA-predicted task times were compared to task times recorded in an empirical simulator study of IVIS interaction, and the predicted times were, on average, within acceptable precision limits. This work forms the foundation for extension of the CPA model to predict IVIS task times in a moving vehicle, to reflect the demands of the dual-task driving scenario.

PRACTITIONER SUMMARY

The CPA method was extended for the prediction of slowperson and fastperson IVIS task times. Comparison of the model predictions with empirical data demonstrated acceptable precision. The CPA model can be used in early IVIS evaluation; however, there is a need to extend it to represent the dual-task driving scenario.

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.

A comparison of two contemporary types of in-car multifunctional interfaces

A driving simulator study was conducted to investigate the effects of carrying out a variety of tasks using two different types of contemporary in-car multifunctional interfaces: a touch screen interface and an interface manoeuvred by a rotary control. Participants drove on a curved rural road while performing tasks such as list scrolling, radio tuning, alphanumeric input and continuous adjustments. The results indicate that, in terms of task completion time and the number of glances made to the display, the optimal interface is dependent on the task being performed. The touch screen interface was better for alphanumeric input tasks and the interface manoeuvred by a rotary control was better for continuous adjustments and list scrolling. Alphanumeric input seems to be more demanding than other tasks, independent of the interface used. It was apparent in this simulator study that both interfaces affected the lateral control performance, but lateral control performance deteriorated to a greater extent when the touch screen interface was used, probably partially as a result of the lower display position.

To twist or poke? A method for identifying usability issues with the rotary controller and touch screen for control of in-vehicle information systems

In-vehicle information systems (IVIS) can be controlled by the user via direct or indirect input devices. In order to develop the next generation of usable IVIS, designers need to be able to evaluate and understand the usability issues associated with these two input types. The aim of this study was to investigate the effectiveness of a set of empirical usability evaluation methods for identifying important usability issues and distinguishing between the IVIS input devices. A number of usability issues were identified and their causal factors have been explored. These were related to the input type, the structure of the menu/tasks and hardware issues. In particular, the translation between inputs and on-screen actions and a lack of visual feedback for menu navigation resulted in lower levels of usability for the indirect device. This information will be useful in informing the design of new IVIS, with improved usability. STATEMENT OF RELEVANCE: This paper examines the use of empirical methods for distinguishing between direct and indirect IVIS input devices and identifying usability issues. Results have shown that the characteristics of indirect input devices produce more serious usability issues, compared with direct devices and can have a negative effect on the driver-vehicle interaction.

Correlation between safety assessments in the driver-car interaction design process

With the functional revolution in modern cars, evaluation methods to be used in all phases of driver-car interaction design have gained importance. It is crucial for car manufacturers to discover and solve safety issues early in the interaction design process. A current problem is thus to find a correlation between the formative methods that are used during development and the summative methods that are used when the product has reached the customer. This paper investigates the correlation between efficiency metrics from summative and formative evaluations, where the results of two studies on sound and navigation system tasks are compared. The first, an analysis of the J.D. Power and Associates APEAL survey, consists of answers given by about two thousand customers. The second, an expert evaluation study, was done by six evaluators who assessed the layouts by task completion time, TLX and Nielsen heuristics. The results show a high degree of correlation between the studies in terms of task efficiency, i.e. between customer ratings and task completion time, and customer ratings and TLX. However, no correlation was observed between Nielsen heuristics and customer ratings, task completion time or TLX. The results of the studies introduce a possibility to develop a usability evaluation framework that includes both formative and summative approaches, as the results show a high degree of consistency between the different methodologies. Hence, combining a quantitative approach with the expert evaluation method, such as task completion time, should be more useful for driver-car interaction design.

Where's the emotion? How sport psychology can inform research on emotion in human factors

OBJECTIVE

The aim of this study was to demonstrate how research on emotion in sport psychology might inform the field of human factors.

BACKGROUND

Human factors historically has paid little attention to the role of emotion within the research on human-system relations. The theories, methods, and practices related to research on emotion within sport psychology might be informative for human factors because fundamentally, sport psychology and human factors are applied fields concerned with enhancing performance in complex, real-world domains.

METHOD

Reviews of three areas of theory and research on emotion in sport psychology are presented, and the relevancy of each area for human factors is proposed: (a) emotional preparation and regulation for performance, (b) an emotional trait explanation for risk taking in sport, and (c) the link between emotion and motor behavior. Finally, there are suggestions for how to continue cross-talk between human factors and sport psychology about research on emotion and related topics in the future.

RESULTS

The relevance of theory and research on emotion in sport psychology for human factors is demonstrated.

CONCLUSION

The human factors field and, in particular, research on human-system relations may benefit from a consideration of theory and research on emotion in sport psychology.

APPLICATION

Theories, methods, and practices from sport psychology might be applied usefully to human factors.

From Intention to Input: Motor Cognition, Motor Performance, and the Control of Technology

Fundamental knowledge of motor cognition is an important component in a human factors repertoire, and this chapter serves as a guide to the history, theory, and application of motor cognition research.“From intention to input” captures the scope of this chapter in that cognitive theories of motor control, neural control of movement, and the effects of feedback on movement are all discussed. The chapter progresses from an overview and history of motor cognition theories down to the neural basis for movement, then to an application of these theories via the study of specific actions. From there, rooted in the scientist-practitioner paradigm of human factors, the chapter covers applied considerations for designing control tasks and their associated inputs, taking into account individual differences in motor cognition and control and identifying critical issues in designing for input. General, applied guidelines are provided for use with current and future systems that have a motor cognition component.

Toward a psychological science of advanced technology design for older adults

OBJECTIVES

Technology represents advances in knowledge that change the way humans perform tasks. Ideally, technology will make the task easier, more efficient, safer, or perhaps more pleasurable. Unfortunately, new technologies can sometimes make a task more difficult, slower, dangerous, or perhaps more frustrating. Older adults interact with a variety of technologies in the course of their daily activities and thus products should be designed to be used by people of varying ages.

METHODS

In this article, we provide an overview of what psychology has to offer to the design of technology-from understanding what people need, to identifying their preferences for design characteristics, and to defining their capabilities and limitations that will influence technology interactions.

RESULTS

We identify how research in the field of psychology and aging has advanced understanding of technology interactions and how research on technology interactions can inform theories of aging.

DISCUSSION

Design for aging involves understanding the unique capabilities and limitations of older adults; identifying their needs, preferences, and desires for technology in their lives; and involving them in the design process.

Using Direct and Indirect Input Devices: Attention Demands and Age-Related Differences

Researchers have suggested that attention is a key moderating variable predicting performance with an input device [e.g., Greenstein & Arnaut, 1988] without directly assessing the attention demands of devices We hypothesized that the attentional demands of input devices would be intricately linked to whether the device matched the input requirements of the on-screen task. Further, matching task and device should be more important for attentionally reduced groups, such as older adults. Younger and older adults used either a direct (touch screen) or indirect (rotary encoder) input device to perform matched or mismatched input tasks under a spectrum of attention allocation conditions. Input devices required attention - more so for older adults, especially in a mismatch situation. In addition, task performance was influenced by the mach between task demands and input device characteristics. Though both groups benefited from a match between input device and task input requirements, older adults benefited more and this benefit increased as less attention was available. We offer an a priori method to choose an input device for a task by considering the overlap between device attributes and input requirements. These data have implications for design decisions concerning input device selection across age groups and task contexts.

Operator-Automation Interaction in Agricultural Vehicles

Over the last 25 years, considerable research has been conducted in an effort to understand human behavior in automated systems. These efforts have yielded a number of valuable findings about the overall nature of human-automation interaction across a wide range of domains, such as aviation, surface transportation, medical systems, manufacturing environments, and maritime vehicles. In this article, we provide an overview of another domain that has been heavily influenced by automation: agricultural vehicles. We share some observations about the impacts of automation on human behavior within this domain, discuss some of the tools and methods being used to investigate these issues, and speculate about the lessons to be learned about human-automation interaction from this arena.

Assessing design features of virtual keyboards for text entry

OBJECTIVE

The present research examined design of a virtual keyboard for text entry with a rotary controller, emphasizing users who differ in age and system experience.

BACKGROUND

Existing research has minimally addressed usage frequency, age, and the effects of display shape and letter arrangement on movement and visual search components of text entry tasks. The present research was conducted to close these gaps.

METHOD

Two experiments were completed to examine younger (18-28 years) and older (60-75 years) adults' movement and visual search capabilities using four keyboard shapes and three keyboard arrangements. In a third experiment examining combined effects on shape design, 32 younger (18-28 years) and 32 older (60-75 years) adults entered words on the two best shapes from the first experiments.

RESULTS

For the movement task, movement time was lowest for shapes with higher shape-controller compatibility. For the visual search task, search time and accuracy were best on the alphabetic arrangement. In the combined task, shape did not significantly influence performance at different levels of practice. Transfers, however, suggested that the shape with salient visual features elicited a text entry strategy for older adults that may promote more consistent performance under occasional usage.

CONCLUSION

The studies together demonstrate that keyboard shape is important for efficient performance. Shape-controller compatibility facilitated performance in both age groups. Salient features facilitate performance, especially for older adults. In nearly all cases alphabetic arrangement yielded the best performance.

APPLICATION

Recommendations are provided for virtual keyboard design for different usage frequencies, contexts, and users.

Environmental support: an integrative framework

OBJECTIVE

In this qualitative review, we develop an integrative framework to bring coherence to the concept of environmental support (ES) in the fields of human factors and cognitive aging.

BACKGROUND

The ES hypothesis, originally formulated to explain effects of retrieval support on age-related differences in memory by reducing need for self-initiated processing, has been applied to many domains, such that the concept now encompasses many manipulations and measures. We developed a framework in which different types of ES share a common function (external support of performance) but differ in how this function is accomplished. ES improves performance by reducing task demands on mental resources or promoting effective use of resources. Previous reviews show that ES can decrease age-related differences in performance (more benefit for older adults), provide equal benefit, or increase differences (more benefit for younger adults). We proposed that the outcome will depend on properties of the ES, task, and person.

METHOD

We applied our framework to the domains of language comprehension and human-computer interaction, selecting studies representative of differing outcomes for ES.

RESULTS

In both domains, we found that outcomes depended on ES, task, and person. Age differences were more likely to be reduced by ES that imposed minimal prerequisites for use and targeted processes that needed support.

CONCLUSION

Our review helps refine the ES concept by identifying conditions under which age differences in performance are reduced or magnified by ES.

APPLICATIONS

The framework provides guidance for human factors practitioners to design tasks and environments for older adults.

Aging and human performance

OBJECTIVES

I identify major theoretical and practical contributions to aging and human performance as reflected primarily in the pages of Human Factors.

BACKGROUND

Populations worldwide are aging. True experimental work on aging is not possible because age levels cannot be manipulated. Sophisticated theoretical frameworks and modeling techniques are required to reach valid inferences about age effects and age changes.

METHOD

Citation analysis was used to identify articles in Human Factors dealing with age or aging and to rank them for citation impact.

RESULTS

Special issues on aging were followed by increased publication rates for articles on age or aging, particularly in the 1990s. Most-cited articles deal primarily with age and driving.

CONCLUSIONS

Applied contributions rely on improved measurement of performance and on methodological advances, including simulation and modeling. Design changes that provide environmental support for declining cognitive, perceptual, and psychomotor abilities can serve as a powerful intervention for maintaining and improving older adult performance. Training is also a robust way to improve performance at both the basic ability level and the level of task performance. Human factors specialists can improve quality of life for an aging population.

APPLICATIONS

Guidelines for older users are now being developed by standards bodies and are implemented in domains such as Web design. Much of the focus of human factors research has been on improving efficiency in the performance of aging adults in the workforce, but reducing errors and increasing comfort and satisfaction in health-related activities should receive greater attention.

The Model Human Processor and the older adult: parameter estimation and validation within a mobile phone task

The authors estimate weighted mean values for nine information processing parameters for older adults using the Card, Moran, and Newell (1983) Model Human Processor model. The authors validate a subset of these parameters by modeling two mobile phone tasks using two different phones and comparing model predictions to a sample of younger (N = 20; M-sub(age) = 20) and older (N = 20; M-sub(age) = 69) adults. Older adult models fit keystroke-level performance at the aggregate grain of analysis extremely well (R = 0.99) and produced equivalent fits to previously validated younger adult models. Critical path analyses highlighted points of poor design as a function of cognitive workload, hardware/software design, and user characteristics. The findings demonstrate that estimated older adult information processing parameters are valid for modeling purposes, can help designers understand age-related performance using existing interfaces, and may support the development of age-sensitive technologies.

Usability of touch-panel interfaces for older adults

The usability of a touch-panel interface was compared among young, middle-aged, and older adults. In addition, a performance model of a touch panel was developed so that pointing time could be predicted with higher accuracy. Moreover, the target location to which a participant could point most quickly was determined. The pointing time with a PC mouse was longer for the older adults than for the other age groups, whereas there were no significant differences in pointing time among the three age groups when a touch-panel interface was used. Pointing to the center of a square target led to the fastest pointing time among nine target locations. Based on these results, we offer some guidelines for the design of touch-panel interfaces and show implications for users of different age groups. Actual or potential applications of this research include designing touch-panel interfaces to make them accessible for older adults and predicting movement times when users operate such devices.