Touch Screen Size Research Articles

Touchscreen device size suitable for non-visual icon search by blind users

Blind smartphone users are on the rise and they need to know which device is easiest for them to use. To explore the optimal touchscreen size for devices used by the blind, we conducted an experiment in which 15 blind participants searched for target icons with four touchscreen devices ranging in size from 4 to 7.9 inches. We analyzed the search time, search strategies, and subjective evaluations and found that the 4.7-inch screen device produced the shortest search time and obtained the highest subjective rating among the four devices. These findings are consistent with those in a previous study with sighted participants. One interesting difference is that the blind participants in this study found the icons about 20% to 40% faster than the sighted participants. Another important finding is that the search strategy had a larger effect than the screen size on the search time. These findings are useful for blind people and their supporters at the stage of obtaining new smartphones and learning how to use them.

Refining distraction potential testing guidelines by considering differences in glancing behavior

Driver distraction is a recognized cause of traffic accidents. Although the well-known guidelines for measuring distraction of secondary in-car tasks were published by the United States National Highway Traffic Safety Administration (NHTSA) in 2013, studies have raised concerns on the accuracy of the method defined in the guidelines, namely criticizing them for basing the diversity of the driver sample on driver age, and for inconsistent between-group results. In fact, it was recently discovered that the NHTSA driving simulator test is susceptible to rather fortuitous results when the participant sample is randomized. This suggests that the results of said test are highly dependent on the selected participants, rather than on the phenomenon being studied, for example, the effects of touch screen size on driver distraction. As an attempt to refine the current guidelines, we set out to study whether a previously proposed new testing method is as susceptible to the effects of participant randomization as the NHTSA method. This new testing method differs from the NHTSA method by two major accounts. First, the new method considers occlusion distance (i.e., how far a driver can drive with their vision covered) rather than age, and second, the new method considers driving in a more complex, and arguably, a more realistic environment than proposed in the NHTSA guidelines. Our results imply that the new method is less susceptible to sample randomization, and that occlusion distance appears a more robust criterion for driver sampling than merely driver age. Our results are applicable in further developing driver distraction guidelines and provide empirical evidence on the effect of individual differences in drivers’ glancing behavior.

Correction to: The extent of mobile accessibility coverage in WCAG 2.1: sufficiency of success criteria and appropriateness of relevant conformance levels pertaining to accessibility problems encountered by users who are visually impaired

People who are blind or visually impaired exhibit different interaction and access needs on mobile touchscreen devices. This is rooted in the reliance on non-visual access for using electronic devices. In comparison to regular computers, non-visual access to mobile touchscreen devices poses more challenges for reasons related to the lack of physical buttons, the limited size of touchscreens, and the reliance on gesture-based interaction. This paper aims at shedding light on the persistent accessibility-related problems that users who are blind or visually impaired are likely to encounter while interacting with mobile touchscreen devices, and whether or not these problems are sufficiently covered in the recent release of Web Content Accessibility Guidelines (WCAG 2.1). The study presented in this paper involved a total of 16 participants with visual impairment cases ranging from moderate vision loss to legal blindness. The results revealed a multitude of critical accessibility problems that are still being overlooked while developing mobile Apps and websites. After compiling all problems, a total of 34 major problems were identified. These problems were then classified into categories with identified nature, severity, and affected demographic. While many of these problems are mapped to existing accessibility guidelines delivered in WCAG 2.1, some problems either lack relevant success criteria in WCAG 2.1 or have insufficient conformance levels in WCAG 2.1. The paper concludes that despite the existence of different mobile-oriented guidelines in WCAG 2.1, there is still an obvious lack of adherence to these guidelines in mainstream mobile content. Moreover, the findings suggest there is room for improvement in WCAG 2.1 to cover more of the problems that users who are blind or visually impaired encounter on mobile touchscreen devices.

Impacts of Touch Screen Size, User Interface Design, and Subtask Boundaries on In-Car Task's Visual Demand and Driver Distraction

• In-car UI design factors’ visual distraction potential should be better understood • First study on UI features’ visual demand while controlling visual demands of driving • Automotive-targeted application decreases glance durations and visual distraction • Larger screen size has relatively small decreasing impact on glance durations • Subtask boundaries enable adjustment of glancing behavior in relation to driving situation • Visual demand of a task is not equal to visual distraction Visual distraction by secondary in-car tasks is a major contributing factor in traffic incidents. In-car user interface design may mitigate these negative effects but to accomplish this, design factors’ visual distraction potential should be better understood. The effects of touch screen size, user interface design, and subtask boundaries on in-car task's visual demand and visual distraction potential were studied in two driving simulator experiments with 48 participants. Multilevel modeling was utilized to control the visual demands of driving and individual differences on in-car glance durations. The 2.5” larger touch screen slightly decreased the in-car glance durations and had a diminishing impact on both visual demand and visual distraction potential of the secondary task. Larger relative impact was discovered concerning user interface design: an automotive-targeted application decreased the visual demand and visual distraction potential of the in-car tasks compared to the use of regular smartphone applications. Also, impact of subtask boundaries was discovered: increase in the preferred number of visual or visual-manual interaction steps during a single in-car glance (e.g., pressing one button vs. typing one word) increased the duration of the in-car glance and its visual distraction potential. The findings also emphasize that even if increasing visual demand of a task – as measured by in-car glance duration or number of glances – may increase its visual distraction potential, these two are not necessarily equal.

P‐203: Frequency Multiplexed Projected Capacitive Touch Screen

Frequency multiplexing projected capacitive (PCAP) touch screens for sensing and addressing overcomes key PCAP challenges which are radio noise sensitivity, connector cable crosstalk, difficult (numerous‐conductor) assembly and strictly limited cable length. One single intelligent controller of this kind is compatible with any frequency multiplexed PCAP touch screen size or resolution.

Recognizing the Operating Hand and the Hand-Changing Process for User Interface Adjustment on Smartphones.

As the size of smartphone touchscreens has become larger and larger in recent years, operability with a single hand is getting worse, especially for female users. We envision that user experience can be significantly improved if smartphones are able to recognize the current operating hand, detect the hand-changing process and then adjust the user interfaces subsequently. In this paper, we proposed, implemented and evaluated two novel systems. The first one leverages the user-generated touchscreen traces to recognize the current operating hand, and the second one utilizes the accelerometer and gyroscope data of all kinds of activities in the user’s daily life to detect the hand-changing process. These two systems are based on two supervised classifiers constructed from a series of refined touchscreen trace, accelerometer and gyroscope features. As opposed to existing solutions that all require users to select the current operating hand or confirm the hand-changing process manually, our systems follow much more convenient and practical methods and allow users to change the operating hand frequently without any harm to the user experience. We conduct extensive experiments on Samsung Galaxy S4 smartphones, and the evaluation results demonstrate that our proposed systems can recognize the current operating hand and detect the hand-changing process with 94.1% and 93.9% precision and 94.1% and 93.7% True Positive Rates (TPR) respectively, when deciding with a single touchscreen trace or accelerometer-gyroscope data segment, and the False Positive Rates (FPR) are as low as 2.6% and 0.7% accordingly. These two systems can either work completely independently and achieve pretty high accuracies or work jointly to further improve the recognition accuracy.

Biomechanical analysis of upper limb during the use of touch screen: motion strategies identification

Nowadays touch technology is growing and developers try to make it ever more intuitive and easier to use. This present work focused on the upper limb joint coordination during the achievement of puzzles on touch screen. A 5-inch and 10-inch devices were used to perform 9 and 16 pieces puzzles dragged with digits. The conclusions showed an increase in joint solicitation with the number of piece and the touch screen size. Moreover, three interactions strategies proved to be an evidence: the ‘wrist strategy’ preferentially implying wrist flexion/extension, the ‘elbow strategy’ preferentially implying the elbow flexion/extension and the ‘neutral strategy’ mobilising equally the two joints. From an ergonomic point of view, the data about how the upper limb segments are mobilised while interacting with the screen could be relevant to increase the adaptability of the devices to the user, including users with motor impairments.Practitioner Summary: Information about the biomechanical organisation of movement during interaction with touch devices appears relevant in order to develop applications adapted to the motor capacities of users. From the analysis of joint angles when performing several times a puzzle with healthy subjects, three motor strategies were highlighted.

An Ergonomic Study on Influence of Touch-screen Phone Size on Single-hand Operation Performance

Touch-screen smart phones have gradually occupied the market of traditional Qwerty Phones and become the mainstream products of mobile phone industry. However, few ergonomics research has been conducted on the touch screens of smart phones, while it has led to tendosynovitis among users owing to the overuse of thumbs. Sizes of smart phones in market range from 3.0 to 7.0 inches. What’s more, 4.0 inches and above are the common size of current touch screens. Also, considering the users’ habits, one-hand operation is preferred when the other hand is occupied. This paper has collected hand parameters of 80 subjects and has adopted an experiment which includes the performance testing and surveys of subjective evaluation by means of usability evaluation. After analysing correlation between touch-screen sizes and operation performances, the result indicates that under one-hand operation, the size of touch screen affects the operation performance significantly. However, it’s hard to implement one-hand operation if the touch-screen size is over 5.7 inches. Additionally, the thickness of smart phones affects the degree of comfort remarkably.

Effects of age, thumb length and screen size on thumb movement coverage on smartphone touchscreens

This study investigated the relationship between the movement coverage on smartphone touchscreens and the factors (age, thumb length and screen size) affecting this. By referring to the thumb movement in the adduction-abduction orientation with a right-hand phone-holding posture, the thumb-coverage area that represents how far the thumb can reach and the centre of gravity in this coverage area were determined. The assessment focused on a comparison of these indices between ages, thumb lengths and screen sizes. The results showed that elderly users and those with longer thumbs are likely to leave more unreachable space at the right side and bottom of touchscreens. Moreover, the thumb-coverage area actually increased when the touchscreen size was increased; however, increasing the size of a smartphone touchscreen does not necessarily increase the thumb-coverage area at the same ratio as the touchscreen size increases.

Mobile input device type, texting style and screen size influence upper extremity and trapezius muscle activity, and cervical posture while texting

This study aimed to determine the effects of input device type, texting style, and screen size on upper extremity and trapezius muscle activity and cervical posture during a short texting task in college students. Users of a physical keypad produced greater thumb, finger flexor, and wrist extensor muscle activity than when texting with a touch screen device of similar dimensions. Texting on either device produced greater wrist extensor muscle activity when texting with 1 hand/thumb compared with both hands/thumbs. As touch screen size increased, more participants held the device on their lap, and chose to use both thumbs less. There was also a trend for greater finger flexor, wrist extensor, and trapezius muscle activity as touch screen size increased, and for greater cervical flexion, although mean differences for cervical flexion were small. Future research can help inform whether the ergonomic stressors observed during texting are associated with musculoskeletal disorder risk.

Touch panel usability of elderly and children

The purpose of this study is to test the usability for the elderly, young adult and children using four different-sized touch panels and to provide suggestions for the elderly and children when using a touch panel. We set the subjects the tasks of dragging, rotating and scaling as quickly and as accurately as possible using different-sized touch panels. In addition to compare the operating performance values for different tasks for the three age groups, this study also recorded the subjects’ hand movements. The results showed that the age and touch screen size had a significant effect on operating performance using the 4.3-in., 10.1-in., 23-in., and 42-in. touch panels. In addition, the average performance value on the touch panels using two hands was higher than the performance using one hand. Some useful and ergonomic interface design guidelines for the elderly and children were also proposed in this study.

A graphical-based password keystroke dynamic authentication system for touch screen handheld mobile devices

Since touch screen handheld mobile devices have become widely used, people are able to access various data and information anywhere and anytime. Most user authentication methods for these mobile devices use PIN-based (Personal Identification Number) authentication, since they do not employ a standard QWERTY keyboard for conveniently entering text-based passwords. However, PINs provide a small password space size, which is vulnerable to attacks. Many studies have employed the KDA (Keystroke Dynamic-based Authentication) system, which is based on keystroke time features to enhance the security of PIN-based authentication. Unfortunately, unlike the text-based password KDA systems in QWERTY keyboards, different keypad sizes or layouts of mobile devices affect the PIN-based KDA system utility. This paper proposes a new graphical-based password KDA system for touch screen handheld mobile devices. The graphical password enlarges the password space size and promotes the KDA utility in touch screen handheld mobile devices. In addition, this paper explores a pressure feature, which is easy to use in touch screen handheld mobile devices, and applies it in the proposed system. The experiment results show: (1) EER is 12.2% in the graphical-based password KDA proposed system. Compared with related schemes in mobile devices, this effectively promotes KDA system utility; (2) EER is reduced to 6.9% when the pressure feature is used in the proposed system. The accuracy of authenticating keystroke time and pressure features is not affected by inconsistent keypads since the graphical passwords are entered via an identical size (50mm×60mm) human–computer interface for satisfying the lowest touch screen size and a GUI of this size is displayed on all mobile devices.

Effect of control-to-display gain and movement direction of information spaces on the usability of navigation on small touch-screen interfaces using tap-n-drag

Tap-n-drag is a popular navigation method for small touch-screen interfaces. When an information space is too large compared to the touch-screen size, navigating the information space using tap-n-drag requires too many drags, resulting in poor usability such as long navigation time or fatigue. In this study, the effect of control-to-display gain on the usability of tap-n-drag was experimentally investigated to determine whether increasing the control-to-display gain can resolve this problem. The effect of movement direction of the information space relative to the drag direction was also investigated (push background vs. push viewport). In experiments, increasing control-to-display gain seemed to increase the usability of tap-n-drag, but excessively large gain seemed to have the opposite effect on some measures such as task completion time, ease of use and overall preference; as a result these measures-vs.-GAIN curves were U-shaped or inverted-U-shaped. Overall, both task completion time and number of touches required to locate a target were lower when using push viewport than when using push background, except at GAIN = 1. Relevance to industry The results of this study can be used to enhance the usability of tap-n-drag and other navigation methods in small touch-screen devices when users navigate a large information space.