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

The research of touch screen usability in civil aircraft cockpit

With the advancement of touch screen technology, the application of touch screens in civil aircraft cockpits has become increasingly popular. However, further analysis and research are required to fully promote its applications. The paper researched the usability of touch screens in aircraft cockpit considering the operation performance and subjective NASA-TLX workload evaluation, conducted experimental research on three touch gestures: click, drag, and zoom. Additionally, a comparative analysis was conducted on the touch performance under different layouts, positions, touch sizes, dragging direction angles, and zoom multiples. The touch performance indicators include operation time, error rate, operation speed, and workload. The experimental results show that the 21 mm size has the minimum operation time and workload, and 18 mm size has the lowest error rate in the clicking tasks. Additionally, the performance and workload of the captain's layout are better than those of the co-pilot's layout, and the performance of the center console position is best. The operation speed of the dragging tasks is faster when performed at position R3 compared to other positions. The dragging moving angles with better operation speed are 80°-190° and 250°-290°. The operation performance and workload of the zooming tasks vary depending on the zoom multiples. As the multiple increases, the operation time and workload also increase. There is no difference in operation performance or workload between zooming in and zooming out. The paper provides experimental support and suggestions based on human operation and subjective NASA-TLX workload evaluation for the application of touch screens in civil aircraft cockpits.

Influence of size and location of buttons on the usability of interface on large touch screens

This study examined how large touchscreen buttons affect user task completion time, error rate, and subjective satisfaction (ease of pointing and clicking on targets). In this experiment, 31 participants completed button click tasks of square targets placed at 30 (5 × 6) different locations, with seven button sizes (10 mm, 30 mm, 50 mm, 70 mm, 90 mm, 110 mm, and 130 mm). Repeated measures ANOVAs showed that on a 65'' large touch screen (W 1428 × H 803 mm), 70 mm buttons achieved essentially the best performance in completion time, 50 mm in error rates, and 90 mm in subjective satisfaction, respectively. We also compare the differences in efficiency among different button areas and button sizes. The surrounding area and lower area require a bigger button size to achieve the best performance in terms of error rates and subjective satisfaction. The right area requires a bigger optimal button size than the left area considering error rates, while it is the opposite for subjective satisfaction.Practitioner summary: This study investigates how the size and location of buttons on the increasingly popular large touch screen affect user experience. The study reveals that 70, 50, 90 mm size buttons are recommended when speed, accuracy and satisfaction are priorities respectively. The interaction between button size and button area is significantly different. The surrounding area and lower area require a bigger button size to achieve the best performance in terms of error rate and subjective satisfaction. Considering error rates, the right area requires a bigger optimal button size than the left area, while it is opposite for subjective satisfaction. These findings could facilitate the optimal design of usable large touch screens.

Elderly Users’ Emotional and Behavioral Responses to Self-Service Technology in Fast-Food Restaurants

While COVID-19 has accelerated digital transformation, increasing labor costs and 52-h workweek rules are replacing human labor with self-service technologies (SSTs). Self-service technology is increasingly being implemented in restaurant settings. However, the elderly, who have relatively lower levels of digital literacy, are being excluded from services that can alleviate the economic and social difficulties of their daily lives. This study thus aims to explain how elderly users feel about and respond to SST in fast-food restaurants. An off-site survey was conducted with individuals who had experience using SST. We analyzed the data using the partial least squares structural equation modeling method by SmartPLS 3.0. The results showed that SST’s reduction, perceived ease of use of SST, and perceived time pressure significantly influenced users’ negative emotions toward the SST. However, perceived physical condition and perceived crowding did not have significant influences on users’ emotions. In empirically investigating individuals’ negative emotions toward and coping strategies for challenges posed by SST, this study emphasizes the development of a nationwide digital inclusion policy that can help bridge the digital divide.

Determinants of intention with remote health management service among urban older adults: A Unified Theory of Acceptance and Use of Technology perspective

Background

Although older adults health management systems have been shown to have a significant impact on health levels, there remains the problem of low use rate, frequency of use, and acceptance by the older adults. This study aims to explore the significant factors which serve as determinants of behavioral intention to use the technology, which in turn promotes actual use.

Methods

This study took a total of 402 urban older adults over 60 years to explore the impact of the use behavior toward remote health management (RHM) through an online questionnaire. Based on the Unified Theory of Acceptance and Use of Technology (UTAUT), the author adds four dimensions: perceived risk, perceived value, perceived interactivity and individual innovation, constructed an extended structural equation model of acceptance and use of technology, and analyzed the variable path relationship.

Results

In this study, the factor loading is between 0.61 and 0.98; the overall Cronbach's Alpha coefficients are >0.7; The composite reliability ranges from 0.59 to 0.91; the average variance extraction ranges from 0.51 to 0.85, which shows the good reliability, validity, and discriminant validity of the constructed model. The influencing factors of the behavioral intention of the older adults to accept the health management system are: effort expectation, social influences, perceived value, performance expectation, perceived interactivity and perceived risk. Effort expectation has a significant positive impact on performance expectation. Individual innovation positively impacts performance expectation and perceived interactivity. Perceived interactivity and behavioral intention have a significant positive effect on the use behavior of the older adults, while the facilitating conditions have little effect on the use behavior.

Conclusions

This paper constructs and verifies the extended model based on UTAUT, fully explores the potential factors affecting the use intention of the older adult users. According to the research findings, some suggestions are proposed from the aspects of effort expectation, performance expectation, perceived interaction and perceived value to improve the use intention and user experience of Internet-based health management services in older adults.

Effect of icon size, icon position and sex on clicking motion when operating smartphones with single hand

Nowadays, increasingly more situations exist where smartphones are operated with one hand, requiring an in-depth understanding of human-computer interaction in single-hand scenarios. 104 volunteers (57 men, 47 women) participated in this study. We aimed to explore thumb movements with the right and left hand on smartphone touchscreens at different icon sizes (50, 80, 110 and 140 rpx) in different operation areas (a 4*7 icon matrix). The results partially conformed to Fitts' Law. The movement time (MT) significantly increased as the icon size decreased, but this effect was not found over 110 rpx. The MT increased with distance in the vertical direction, but icons with the same horizontal distance had different MTs, indicating that one-handed operation restricted the click on the same side. Additionally, subjects rated 140 rpx better than other sizes, and men clicked faster than women. Suggestions regarding one-handed interface design for different hands of different sexes are provided. Practitioner summary: This study investigated how icon size, position and sex influenced one-thumb click usability on touch-screen mobile phones with different hands of different sexes. The results indicate single-hand operation partially conformed to Fitts' Law. We suggested the most economical and comfortable size and the fast operation area in one-handed interface design.Abbreviations: MT: movement time; ID: index of difficulty; RPX: responsive pixel; NASA-TLX: task load index of National Aeronautics and Space Administration; ANOVA: analysis of variance.

The impact of different age-friendly smart home interface styles on the interaction behavior of elderly users

Smart homes create a beneficial environment for the lives of elderly people and enhance the quality of their home lives. This study aims to explore the design of age-friendly interfaces that can meet the emotional needs of self-care elderly people from the perspective of functional realization of the operating interface. Sixteen elderly users aged fifty-five and above were selected as subjects with healthy eyes and no excessive drooping eyelids to obscure them. Four representative age-friendly applications with different interface designs were selected from the Android application market as the stimulus material for the experiment, and a total of fifteen pages were browsed independently. During the experiment, the ErgoLAB human-computer environment synchronization cloud platform was used to monitor and record the subjects' multidimensional physiological indicators of eye movements, skin electricity, and heart rate variability when using different styles of mobile application interfaces. Combined with the post-experimental PAD emotion scale data, the preferences of emotional interface design elements of the self-care elderly were analyzed to guide the subsequent design practice. The results show that: on the layout characteristics of the home page, a simple and intuitive multi-column layout or card layout combined with a bottom navigation bar type main navigation is used; on the choice of the main color, a single color with low saturation is used as the main color, with high saturation color accents to play a role in highlighting key information; on the information density of the home page, a moderate proportion of graphics and text is adopted, with low information density; on the arrangement of the page content, they try to give priority to information content with high user relevance.

Mobile health applications for older adults: a systematic review of interface and persuasive feature design

OBJECTIVE

Mobile-based interventions have the potential to promote healthy aging among older adults. However, the adoption and use of mobile health applications are often low due to inappropriate designs. The aim of this systematic review is to identify, synthesize, and report interface and persuasive feature design recommendations of mobile health applications for elderly users to facilitate adoption and improve health-related outcomes.

MATERIALS AND METHODS

We searched PubMed, Embase, PsycINFO, CINAHL, and Scopus databases to identify studies that discussed and evaluated elderly-friendly interface and persuasive feature designs of mobile health applications using an elderly cohort.

RESULTS

We included 74 studies in our analysis. Our analysis revealed a total of 9 elderly-friendly interface design recommendations: 3 recommendations were targeted at perceptual capabilities of elderly users, 2 at motor coordination problems, and 4 at cognitive and memory deterioration. We also compiled and reported 5 categories of persuasive features: reminders, social features, game elements, personalized interventions, and health education.

DISCUSSION

Only 5 studies included design elements that were based on theories. Moreover, the majority of the included studies evaluated the application as a whole without examining end-user perceptions and the effectiveness of each single design feature. Finally, most studies had methodological limitations, and better research designs are needed to quantify the effectiveness of the application designs rigorously.

CONCLUSIONS

This review synthesizes elderly-friendly interface and persuasive feature design recommendations for mobile health applications from the existing literature and provides recommendations for future research in this area and guidelines for designers.

Analysing Touchscreen Gestures: A Study Based on Individuals with Down Syndrome Centred on Design for All

There has been a conscious shift towards developing increasingly inclusive applications. However, despite this fact, most research has focused on supporting those with visual or hearing impairments and less attention has been paid to cognitive impairments. The purpose of this study is to analyse touch gestures used for touchscreens and identify which gestures are suitable for individuals living with Down syndrome (DS) or other forms of physical or cognitive impairments. With this information, app developers can satisfy Design for All (DfA) requirements by selecting adequate gestures from existing lists of gesture sets. Twenty touch gestures were defined for this study and a sample group containing eighteen individuals with Down syndrome was used. A tool was developed to measure the performance of touch gestures and participants were asked to perform simple tasks that involved the repeated use of these twenty gestures. Three variables are analysed to establish whether they influence the success rates or completion times of gestures, as they could have a collateral effect on the skill with which gestures are performed. These variables are Gender, Type of Down syndrome, and Socioeconomic Status. Analysis reveals that significant difference is present when a pairwise comparison is performed, meaning individuals with DS cannot perform all gestures with the same ease. The variables Gender and Socioeconomic Status do not influence success rates or completion times, but Type of DS does.

Effects of control-to-display gain and operation precision requirement on touchscreen operations in vibration environments

Touchscreen has gained increasing popularity. However, little is known about touchscreen use in vibration environments. This study aimed to examine the effects of control-to-display gain (GAIN) and operation precision requirement on touchscreen operations in varied vibration environments. Twenty participants attended an experiment where they were instructed to perform three types of basic touchscreen operation tasks in static, low vibration, and high vibration environments, respectively. Five GAINs (0.75, 1, 2, 3 and 4) and three operation precision requirements (90%, 95%, and 99%) were examined. The results indicated that vibration exerted adverse effects on task performance, and increased perceived workload, perceived task difficulty and discomfort. Task completion time showed a U-shaped curve as GAIN increased. Lowering operation precision requirement improved task performance and reduced perceived workload, especially in vibration environments and at larger GAINs. The findings provide practical implications on the design of usable touchscreen interfaces in vibration environments.

The development of a mobile user interface ability evaluation system for the elderly

This research aimed to develop a comprehensive evaluation of the mobile user interface abilities of the elderly so that technology can be designed to meet individualized needs. A total of 135 older adults were evaluated with the developed system, the Elderly Mobile User Interface Ability Evaluation System (EMUIAES). The prediction of age and the use of technology on elderly mobile interface usage were investigated based on the findings of the evaluation. The relationship between performance on Fitts' task and elderly mobile user interface ability (EMUIA) was also examined. The findings showed a strong effect of age on the elderly's use of mobile user interfaces. Previous experience with personal and tablet computers also contributed to the use of mobile user interfaces. In addition, this research demonstrated the application of Fitts' law to describe the elderly mobile user interface behaviors, particularly for tasks involving fast tapping and pointing. The EMUIAES can provide future researchers and designers a comprehensive tool to describe the elderly's diverse behaviors and changes in their ability to use mobile interfaces. Individualized interface designs for elderly users can be developed based on these findings to improve the elderly users' experiences of using technology.

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.

Prediction of the use of mobile device interfaces in the progressive aging process with the model of Fitts' law

PURPOSE

As the population ages, so do the potential users of technology, and older adults' behaviors when using mobile device interfaces are becoming increasingly important. A representative model for detecting older adults' behaviors and performance on the use of mobile device interfaces is needed to provide individualized designs. This research aimed to investigate the applicability of the broadly used model of Fitts' law to detect the progressive changes in the use of mobile device interfaces in older adults. The effect of experience with using technology on performance on a Fitts task was also examined.

METHOD

A sample of 135 older adults was recruited to test the application of Fitts' model to the use of technology by older adult users. Each participant was asked to finish tasks at 9 levels of difficulty, from easy to difficult, in a multidirectional tapping task. Analysis of variance was employed to examine the effect of age on performance on the Fitts task, movement time, and the standard deviation of movement time. Stepwise regression was used to investigate how well age and technology use could predict performance on the Fitts task.

RESULT

Performance on the Fitts task was sensitive to the gradual changes in abilities with aging. Rather than the amount of experience in using technology, age was the stronger predictor of older adults' performance on the Fitts task. Additionally, compared with the younger groups, the users above 80 years old demonstrated significantly higher behavioral variation during the use of mobile device interfaces.

CONCLUSION

This research confirmed that Fitts' law is applicable to the evaluation of the effects of aging on the use of mobile device interfaces. Adults above the age of 80 years should be a major focus for special individualized interface design. This finding can inform future designers and researchers in the development of individualized interface designs for older adult users to enhance their user experiences of mobile device technology.

RELEVANCE TO INDUSTRY

Future designers and researchers can apply the finding on Fitts' law in this research to develop user-friendly interface designs for mobile technology for older adults and thereby improve their user experiences to enhance their independence and quality of life through the use of technology.

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.

Investigation of force, contact area and dwell time in finger-tapping tasks on membrane touch interface

This study aimed to determine the touch characteristics during tapping tasks on membrane touch interface and investigate the effects of posture and gender on touch characteristics variables. One hundred participants tapped digits displayed on a membrane touch interface on sitting and standing positions using all fingers of the dominant hand. Touch characteristics measures included average force, contact area and dwell time. Across fingers and postures, males exerted larger force and contact area than females, but similar dwell time. Across genders and postures, thumb exerted the largest force and the force of the other four fingers showed no significant difference. The contact area of the thumb was the largest, whereas that of the little finger was the smallest; the dwell time of the thumb was the longest, whereas that of the middle finger was the shortest. Relationships among finger sizes, gender, posture and touch characteristics were proposed. The findings helped direct membrane touch interface design for digital and numerical control products from hardware and software perspectives. Practitioner Summary: This study measured force, contact area and dwell time in tapping tasks on membrane touch interface and examined effects of gender and posture on force, contact area and dwell time. The findings will direct membrane touch interface design for digital and numerical control products from hardware and software perspectives. Abbreviations: M: mean; SD: standard deviation; ISO: International Organization for Standardization; LCD: liquid crystal display; ANOVA: analysis of variance; ANSI: American National Standards Institute; HFES: Human Factors and Ergonomics Society.

Effects of touchscreen gesture's type and direction on finger-touch input performance and subjective ratings

This study examined how finger-touch input performance (i.e. task completion time, failure status, and error rate) and subjective ratings (i.e. performance and physical demand) are influenced by touchscreen gestures' type and direction. Twenty participants performed one-touch (i.e. drag and swipe) and two-touch (i.e. pinch and spread) gesture tasks on a tablet, using several major directions (i.e. eight directions for one-touch and four directions for two-touch gestures). The results showed that swipe was approximately 4.5 times faster than drag, but pinch and spread showed no significant difference in task completion time. Dragging and pinching showed more failures or higher error rates compared to swiping and spreading, respectively. One-touch gestures in the horizontal directions were rated to have higher performance and lower physical demand than those in the vertical and diagonal directions. Two-touch gestures in the horizontal directions took the shortest time but caused more failures and higher error rates. Practitioner Summary: This study provides evidence for the effects of touchscreen gestures' type and direction on human performance and subjective ratings, which varied depending on the number of fingers used. Designers should arrange related touchscreen components accordingly, to improve touch-finger input performance and reduce user workload.

Touchscreen interfaces in context: A systematic review of research into touchscreens across settings, populations, and implementations

Although many studies have been conducted on the human factors and ergonomics (HFE) of touchscreens, no comprehensive review has summarized the findings of these studies. Based on a schema (three dimensions of understanding critical for successful display selection) presented by Wickens et al. (2004), we identified three dimensions of analysis for touchscreen implementations: touchscreen technology, setting and environment of implementation, and user population. We conducted a systematic review based on the PRISMA protocol (Moher et al., 2009), searching five article databases for relevant quantitative literature on touchscreens. We found that all three dimensions of analysis have a significant effect on the HFE of touchscreens, and that a selection for or against touchscreens must take into consideration the specific context of system interaction in order to maximize safety, performance, and user satisfaction. Our report concludes with a set of specific recommendations for systems designers considering touchscreens as input/output devices, and suggestions for future study into the HFE of touchscreens.