Keywords

1 Introduction

Amid the fast-growing technological landscape, the visual and touch displayer remains a main form of information presentation in the interface of many mobile devices. The current interface of mobile devices like smart phones has significantly facilitated our life. Against such a backdrop, many apps of smart phones have been developed to offer diverse services, including the online payment, the modification of photos, FB, Instagram, LINE and WeChat. Many countries across the world have encountered the problem of an aging population. Early in 1993, Bouma and Graafmans (1992) gave the first definition of the technology for the well-being of the elderly: “the technology for the well-being of the elderly is based on the knowledge of aging and focuses on the development of relevant technological and scientific products; it aims to provide the elderly with a sound environment for life and work as well as the supporting medical care”.

As smart mobile devices have been adopted by the public and become an indispensable part of people’s daily life, whether the operating gesture of these high-tech products is appropriate has become a topic of the academic research on the use of cell phones among the middle-aged and the elderly and on technological innovation.

Multi-functional mobile devices have gradually become ubiquitous devices for information transmission in the daily life and served as an indispensable tool for modern people. An essential service of the present-day technological products is to bring accurate information immediately and send message at any time. E-book reader, tablets and smart touch phones are highly prevalent today. Like a laptop, they are equipped with such functions as the Internet access and document editing and with a screen as big as that of a laptop; moreover, they are lighter and thinner. Therefore, they have evolved into a product of smart mobile device interface which can substitute laptop in recent years.

Additionally, the ever-changing cloud service has contributed to the rapid development of smart mobile devices and satisfied the needs of the users with various mobile services. This has greatly fueled the vigorous development of the mobile device market. For instance, Microsoft has always strived to make their products more efficient, exquisite and humanized (Microsoft surface, 2017). Pitt et al. (2010) argued that smart mobile devices should have the following features: (1) the interface can be controlled through multi-point touch; (2) the hardware is equipped with an acceleration sensor to capture more subtle control based on hand movement, so that the users would have a better access to the Internet and games or finish their tasks in a more efficient way. It is obvious that considering the factors which influence the touch gesture of the elderly to create an operating gesture model which meets the needs of the elderly will greatly benefit the aged. There will be new designs of various touch mobile devices in the future.

These devices will not only possess the advantages of the existing ones but also offer a better touch operating gesture, which will solve the problems in the learning memory among the middle-aged and the elderly and help them acquire the information on the interface of mobile devices in a more efficient way. In the book The Design of Everyday Things published in 2013, Norman proposed the function of natural mapping which could help the users memorize complex information and make the use more efficient. For the elderly, it is rather confusing to think if a product can meet their needs.

As industrial designers, we should be clear about the needs of the elderly and offer the operating gesture suitable for the users according to the principle of general design. According to the research reports on the interface of smart touch devices, the elderly spend more time in getting used to the operation of relevant products. For the old people with clumsy upper limbs, the operation is even more challenging. To date, few studies on the design of the operation gesture of smart phones for the elderly have been done. In terms of gesture control, there have been a wide range of approaches which can be roughly divided into two groups – the two-dimensional gesture and the three-dimensional one.

In a broad sense, they refer to the operation based on the finger or hand touch on the screen in the space of free movement. This study attempts to develop an innovative gesture design model for the operating gesture of smart mobile devices, with the hope of developing the most intuitive and natural gesture operation for the best interaction between products and the elderly. In the innovative gesture design model, only one finger is used for the operation, which is more beneficial for the elderly than the existing operating gestures.

2 Literature Review

According to the authors’ relevant studies, the demand for and the understanding of the operation of smart interface devices would change with aging. The young have a better command of technological products because of their excellent physiological state. They perform better than the middle-aged and the elderly in the familiarity with the use and the reaction to the interface operation. In the social structure with increasing aging, the elderly should be able to operate smart interface devices in a more intuitive and efficient way. This will be an issue worthy of special attention in the future.

Today, high-tech products are developing with each passing day, and different brands have launched a multitude of smart mobile interface products. In respect of product value, they emphasize environmental protection, safety, device efficacy and innovative entertainment. Nevertheless, the color of the words on the interface, the product feedback mechanism, the presentation and lightness of the screen, the size of the floating window, and the use gesture often attract less attention. Consequently, a user has to get accustomed to a different operation if he/she buys the products of a new brand; worse still, a different operating gesture requires many attempts, which would result in learning fatigue and even giving up. As for the smart mobile devices where object is selected with only one finger, Saffer (2009) suggested that they should include “tap to select”, “slide to scroll”, “spin to scroll, and “flick to nudge”.

These gestures on the screen interface, which lead to more visual information, are taken as the common gestures, as is shown in Fig. 1. In this study, the authors summarized the types of operating gestures of the common smart phones in the market and found three most frequently-seen operating gestures, namely, “move”, “spin” and “zoom”. The introduction to the summarized operating gestures is shown in Table 1. The findings of the study by Wang et al. (2015) and Liu (2016) show that it is difficult for the elderly to operate smart mobile devices with two fingers.

Fig. 1.
figure 1

Common gestures

Fig. 2.
figure 2

The finger movement gestures

Fig. 3.
figure 3

The finger movement gestures

Fig. 4.
figure 4

Spin gestures

Fig. 5.
figure 5

Zoom in and zoom out gestures

Table 1. Types of existing smart phones and their operating gestures

Finally, the study proposed the new gesture control model featuring one-finger operating gesture, and the comparison based on the data obtained from the evaluation of feasibility show that the new operating gesture was better than the traditional operating model. Besides, the concepts of human factors engineering are applied to the establishment of the decision-making and evaluation system, the design of modeling development and the presentation development, so as to improve the operating gestures of the elderly on the interface of mobile devices.

This study transforms the preliminary results into products that can be further realized in the future. The present invention relates to a method of using single finger for operating touch screen interface. The method for performing a scaling up/scaling down operation comprises: touching a left side region or a right side region of a screen of a mobile device for a predetermined time; displaying a scaling up/scaling down operation interface on the screen of the mobile device; and moving upward or downward to perform a scaling up/scaling down operation. The present invention provides a more intuitive and convenience operation interface, especially for the elderly or disability operator (as is shown in Fig. 6).

Fig. 6.
figure 6

The non-provisional application claims prioriy from Taiwan patent application no. I-543068, filed on July 21, 2016, the content thereof is incorporated by reference herin.

A more detailed description of the above operating gestures (move, spin and zoom) is as follows:

  1. 1.

    Move: Place one finger on the displayer of the smart mobile device and press the pictures and message to be moved for 5 ms. Then, the visual effect of mobility will be presented. The finger movement is shown in Figs. 2 and 3.

  2. 2.

    Spin: Currently, spin is an implicit function in most mobile devices in the market; hence, few people know how to initiate the function nor how to operate (as is shown in Fig. 4) when they want to view pictures or have them edited.

  3. 3.

    Zoom: At present, most smart mobile devices adopt the same operating gesture for zooming, where two fingers are placed on any point of the screen. If the two fingers move apart, there will be “zoom in”; if they move towards each other, there will be “zoom out”, as is shown in Fig. 5.

3 Method

This study adopted the focus group interview to define the operating gestures of smart mobile devices which were the most difficult for the elderly. Then, the three difficult operating gestures (zooming, image capture and spinning) were emphasized. First, 10 subjects used the smart mobile devices familiar to them to perform the three operating gestures. Second, this study turned four experimental samples into an animation and played it for the subjects, so that they learned how to operate the new gesture design model. Finally, the preference of the subjects was measured (“Interested in it”, “Want to use it”, “Not interested in it”, and “Don’t want to use it”).

3.1 Focus Grouping

  • Sample products

    The operating gestures of the majority of present-day smart mobile devices were taken as the experiment samples, and the gestures were divided into “Spin”, “Zoom”, “Capture image” and “Combined gesture”, as is shown in Table 2. With focus on the operating gestures of smart mobile devices among the people aged over 55, this study adopted literature review, questionnaire survey and experiment simulation operation to propose the operating gestures suitable for the elderly; meanwhile, the use evaluation items by Nielsen (1992), including “Learning”, “Efficiency”, “Memory”, “Error”, “Convenience” and “Overall satisfaction” were taken into account.

    According to Vercruyssen (1996), it was impossible for the elderly to maintain long-term attention and the elderly would feel very tired when asked to do fast or successive scanning. Moreover, they could not make correct judgment if they were asked to finish two or more complicated tasks at the same time (Hartley 1992; McDowd and Craik 1988).

  • Subjects

    The average age of the 10 middle-aged and elderly subjects of this study is 60.7, and all of them have used smart mobile devices for over 1 year.

  • Process

    First, the subjects were shown the samples of the four operating gestures and how to perform them (for about 5 min). Then, each subject watched the animation (for 10 min) to define which operating gesture is the most suitable for the elderly. Finally, an interview was held with each of the subjects.

3.2 The Subjects’ Preference for the Four Operating Gestures

Table 2. Descriptive Statistics

4 Result

In this study, a human factors investigation into the elderly who have used common touch mobile devices was conducted to detect the problems in the operating gestures of the elderly and summarize the recognitive factors, concentration and preference of the elderly in the use of touch gesture message. Then, the main factors were adopted for the human factors engineering recognition experiment, and we observed the preference of the elderly for the operating gestures in the operation of the touch mobile devices.

Moreover, a subjective scale was employed to measure the significant difference in operating gesture among the elderly. According to the preliminary classification of the common smart phones, the frequently-used operating gestures are “Move”, “Spin” and “Zoom”. Besides, previous studies and the literatures show that “Spin”, “Zoom” and “Capture image” are the three most difficult operating gestures for the elderly.

According to the results of the questionnaire survey on the four innovative operating gestures developed in this study, Sample 1 is the least popular. Some subjects didn’t show much interest in Sample 2. Most subjects regarded it as ordinary and found it easy to understand the operation, so there wasn’t any strong response to it. What surprised us most were Sample 3 and Sample 4. Most of the subjects were interested in the two operating gestures and want to perform them in reality. The interview indicated that they were curious about the combined gesture (zoom and spin) and the side-zooming.

5 Conclusion

In this study, an innovative interface operating gesture system was designed to reduce the fear and helplessness of the elderly in the operation of smart mobile devices and improve the design of the existing interface operating gestures of smart mobile devices. After probing into the type, method, principle and relevant literatures of the interface operation of smart mobile devices, this study proposed the intuitive operating gestures which are more suitable for the middle-aged and the elderly and analyzed the key factors which influenced their operating gestures and intuition.

By summarizing the design principles and parameters suitable for the development of the interface system of smart mobile devices and delving into the operating gestures and intuition of the middle-aged and the elderly as well as the subjective measurement, this study aims to develop a better gesture-operating system for smart mobile devices to meet the trend of the aging society and create more humanized products to satisfy their needs and improve their life.