Design Methods for the Elderly in Web of Science, Scopus, and China National Knowledge Infrastructure Databases: A Scientometric Analysis in CiteSpace

Abstract

With the increasing aging population globally, issues that come with aging are becoming more severe. This prompted the governments and society to focus on the social security of the elderly. To guarantee the safety of the elderly, satisfy their emotional requirements, and assist them in adapting to a fast-changing socio-technical environment, researchers have proposed many design methods. Various researchers have studied the relevant literature and design techniques for the elderly. However, it was discovered that China is second, followed by the United States, in terms of research impact in this area. We used the literature from China National Knowledge Infrastructure (CNKI) for China. We selected 1221 papers on geriatric design techniques from the Web of Science and Scopus (W&S) and CNKI. Bibliometrics analysis was used to evaluate the current state, development process, and future trend of research on the design methods for the elderly. The findings indicated that (1) the number of studies on geriatric design approaches in W&S and CNKI is rising every year, and (2) the accentuation and complementarity of W&S and CNKI are distinct. It will be a crucial area of study in the future to develop more pleasant and convenient goods and services for the elderly, as well as to address their emotional needs and experiences.

1. Introduction

According to the World Health Organization, the global population aged 60 and above will increase from 12% in 2015 to 22% in 2050 [1]. With the steady increase in the global elderly population and the continuous development of the concept of sustainable development, improving the quality of life of the elderly by creating a good living environment has become increasingly important. The perception, physiology, memory, and attention of the elderly are constantly deteriorating. Therefore, researchers need to propose design methods suitable for this population while taking sustainable development into account. In doing so, the quality of life and independent living ability of the elderly can be improved. Summarizing previous research on the design methods for the elderly can help promote the sustainable development of these methods. One of the pillars of sustainable development is the social well-being of the society [2]; thus, improving the well-being of the aging population is part of improving this social aspect of sustainable development.

Sustainability is primarily a human-centered approach. Therefore, the challenges posed by population aging must be considered from a sustainability perspective. Sustainable aging refers to one’s ability to live safely and independently at home during the aging process [3]. This concept is at the intersection among “active aging”, “healthy aging”, “aging in place”, and “living environment design” [4]. Beyond the biological and medical aspects of aging, “healthy aging” provides a highly holistic perspective that includes subjective experiences and meaning and emphasizes the functional definitions of autonomy, participation, and well-being [5]. The main aspect of “active aging” is to remain healthy and physically active for as long as possible and participate in social, cultural, economic, and spiritual activities [6]. The main aspect of “aging in place” is to solve the daily life difficulties faced by the elderly while living at home, improve their ability to live independently, and prolong their years of independent living. “Living environment design” refers to the overall design of various natural and social conditions that are closely related to human life, including architecture, landscape, space, and environment design.

Numerous goods, tools, and technologies are available to assist the elderly. Their success, however, is dependent upon whether they are built keeping the elderly in mind, which involves the awareness of and design principles that consider the requirements, skills, and preferences of different groups of older individuals. Studies on design methods involving the elderly are also ongoing. To realize sustainable aging, scholars and experts worldwide have thoroughly discussed existing design methods for the elderly from the perspectives of architecture, landscape, product, interface, medical treatment, and technology. The Web of Science (WoS) and Scopus databases cover nearly all the most comprehensive and definitive logical literature available globally. Herein, we collected and sorted out the literature on design methods available in these databases about the elderly and analyzed the research interest of different countries; this analysis indicated that China’s interest in this field is second, followed by the United States. Being the country with the largest population of the elderly, China’s researchers have been extensively studying the design methods for the elderly; thus, Chinese scholars have published a considerable amount of significant research findings. Since the research findings published in Chinese are equally important, it is crucial to summarize the results of the global research on the design methods for the elderly from both the English language-based and Chinese databases. China National Knowledge Infrastructure (CNKI) is the most abundant information resource and the most effective academic literature database for knowledge dissemination in the country. It effectively complements the English language databases and shows the research status of design methods for the elderly in China.

Using bibliometrics and CiteSpace software, this study analyzed the state of research, development process, and prospective trend in design approaches for the elderly using 566 documents in WoS and Scopus (W&S) and 655 documents in CNKI as examples. Other than comparing the literature in the three databases, we comprehensively studied the literature on design methods for the elderly from multiple sources and conducted a network analysis on the annual number of publications, subject distribution, research history, highly cited research, literature keywords, key research platforms, disciplines, and research hotspots. Finally, based on the findings of this study, we further explored the frontier and potential development trends of design methods for the elderly so that researchers, practitioners, and policymakers can gain a better understanding of the relevant research progress from this study, and it can serve as a useful reference for future studies [7].

2. Literature Review

Sustainable design is a comprehensive design that coordinates the relationship among people, environment, enterprises, and societies and allows them to develop together with an aim of reduce pollution and energy consumption, allocate resources rationally, build better lives, and promote the harmonious and healthy development of people and things [8,9]. As the physiology and cognition of the elderly are deteriorating, designers and researchers need to put forward design methods from the perspective of life sustainability that ensures both the healthy living of the elderly and the sustainable development of the environment. The research on the design methods for the elderly mainly focuses on product design, human–computer interaction, interface design, architectural and environmental design, software application design and development, technical innovation and medical treatment, etc. In comparison, most other research is conducted from the perspective of product design. For example, a series of design principles covering functions, structures, appearances, and other details have been proposed to aid in the design of products that can be easily used by the elderly [10]. According to the physical and psychological characteristics of the elderly, Li [11] summarized the principles of functionality, ease of use, emotionality, safety, and modularity in the design of smart wheelchairs for the elderly. Miao and Zhu [12] proposed several design principles that aim to improve the quality of mobility aids developed specifically for the elderly suffering from mild and moderate strokes and those with reduced mobility due to reduced physical functions. Noguchi et al. [13] discussed a case of using social robots, in which they were deployed as human mediators to communicate remotely between older adults and their family members or friends, and they proposed design guidelines for such socially mediating robots. Duarte et al. [14] developed a method to construct the orthosis design process, considering the equipment lifecycle and the different stakeholders’ involvement in the design process. Mincolelli et al. [15] proposed an assessment of the principle of the integration between the limitations arising from the choice of technology used on a device and the human needs obtained from the analysis of the needs of the elderly in the field of designing wearable smart objects for self-sufficient and non-self-sufficient users. Ning et al. [16] designed a wheelchair with the function of posture adjustment, overcoming obstacles to meet the needs of elderly wheelchair users who want to change their body posture in complex environments to facilitate life and free movement. The high correlation between the use of mobile phones, social activity, and environmental awareness of the elderly suggests that the design methods for the elderly can increase their satisfaction with product use and subsequently improve their communication with their social environments [17]. In the product design for the elderly, scholars created the auxiliary design of equipment and tools around the elderly from multiple angles and proposed corresponding product design guidelines, which provided more convenience for the elderly in their daily lives. Naturally, the design of products has become a focal point of the design method research for elderly-friendly products.

Research on human–computer interaction and interface design is also widely reported in journals and conferences. Zhang [18] investigated 52 elderly users using ATMs and found that there were three factor types in the cognitive characteristics of the elderly that affected how the elderly used ATMs. Zhang then proposed corresponding design principles based on the specific issues involved in the three factor types and analyzed the feasibility of these principles. Several principles that guide the interface designs of elderly products have also been proposed by analyzing the current situation of the elderly [19]. Cai and Chen [20] used the rice cooker interface as a research tool and proposed that the interface design of such products should be simplified based on functional accordance (FA), conventional accordance (CA), and physical accordance (PA). According to Cai and Chen, the design that considers FA would reduce the cognitive load on the elderly, CA would be based on their experience and knowledge, and PA would help the design to be presented concisely and consistently. Questionnaire surveys and interviews have been conducted to guide the design of social media interfaces for the elderly [21]. Martins et al. [22] described the analysis and redesign of digital interfaces for the elderly and broader design guiding principles (DGP) recommendations. These DGPs fall into three categories: advanced user features, learning process, and UX (user experience)/UI (user interface) design. Yi and Feng [23] combined the design methods and processes of the home care intelligent service system, as well as the three-level interface interaction design principles of vision, interaction, and reflection, to construct a home care intelligent service system platform. It provided a new way of thinking for the design and provision of intelligent service system products for the elderly at home and made an important contribution to society’s care for the elderly and the improvement in the quality of life.

In terms of architecture and environmental design, Li [24] focused on analyzing the key points of the space design of senior care buildings, from planning and architectural design to detail design, and proposed relevant scientific and reasonable suggestions for their architectural design. The factors of the living environment of the elderly, including their comfort, safety, and diversification, are considered while formulating the design principles of living environments for this population [25]. Jiang et al. [26] proposed to include ecological design concepts in terms of environmental protection, decoration, sound, light, water, waste, heat, and other environmental aspects to optimize the environmental protection scheme for elderly living, which helps enhance their “sense of access”. Martins et al. [27] provided design guidelines for the environment built for the elderly so that the building is more suitable to the occupants’ needs, helps reduce heat-related vulnerabilities, improves the sense of well-being, minimizes the dependence on heating and cooling, and reduces energy use. Stair walking has been used as a health deterioration indicator in the development of an objective index that assesses the challenges faced by the elderly in their activities of daily living (ADLs). The effect of stair size on the relationship between this index and health deterioration is then analyzed to inform the development of design guidelines for elderly health monitoring [28]. Bennetts et al. [29] aimed to improve the thermal environment of Australian elderly housing by investigating the thermal comfort of elderly people living independently in South Australia and formulating thermal comfort guidelines for local aging people.

Other studies focus on software application design and development. For example, Soldati et al. [30] proposed some game design concepts to promote social interaction between the elderly and other generations of players. These games were mainly aimed at relatives. The purpose was to make their visit a pleasant and positive experience and to increase the happiness of all relevant personnel. Bergquist et al. [31] developed three smartphone applications, including the Timed Up and Go (Self TUG), tandem stance (Self-tandem), and Five Times Sit-to-Stand (Self-STS) tests to test the usability of self-testing of elderly body functions. Zhao et al. [32] provided a specific analysis of how to design an app for seniors to live healthily and stay healthy, taking into account their experiences. The purpose was to remind the elderly to take medicine on time, rest on time, eat reasonably, and help plan and develop a healthy lifestyle.

Simultaneously, technical innovation and medical treatment are still worthy of attention, and their research results and conclusions are enlightening. Elias et al. [33] designed a new technology (voice control that can be used at home) to encourage the happiness and autonomy of the elderly who have lost autonomy. Flor-Montalvo et al. [34] used Social Life Cycle Analysis (S-LCA) technology in the routine physical exercise program of the elderly to fully assess the impact of such activities. It was concluded that the execution phase of the program was the phase that produced the most positive impact, and the impact of design and programming was much more significant than expected. Lee and Bae [35] designed a suitable technical aid urine tester to provide medical services for the elderly and vulnerable groups, monitor their health status every day, and remotely help them determine whether to go to the hospital/clinic for in-depth diagnosis.

Studies that use bibliometrics in reviewing the literature on the design methods for the elderly remain scarce and are mainly conducted from a sustainability perspective. For example, Jiang et al. [36] conducted a bibliometric review of the recent publications on sustainable product designs and the keywords used in the Web of Science database. Geng et al. [37] proposed the concept of user-oriented sustainable design by using keywords related to sustainable design and user-centered design to obtain articles from the Scopus database. Chen et al. [38] analyzed articles from the Web of Science database by combining the literature clustering and bibliometric methods and systematically reviewed the research progress in sustainable product and service system design.

The existing bibliometric literature mainly analyzes some dimensions of design methods for the elderly but does not comprehensively analyze the overall status of this field. In addition, these articles mainly come from English databases. CiteSpace can help us track the research progress in this area and predict its future development trend to comprehensively evaluate the overall situation of this field. Therefore, to get more systematic and comprehensive research results, we combined a Chinese-language-based literature database (e.g., CNKI) with an English-language-based literature database (e.g., Scopus, WoS) and systematically discussed the research trends available in these databases on design methods for the elderly.

3. Data and Research Methods

3.1. Data Sources

CNKI is China’s largest and most frequently updated database of Chinese academic literature. WoS is the world’s largest and most comprehensive academic information repository, spanning the majority of academic fields. It is a collection of the most prestigious academic publications over a range of areas of study, such as natural sciences, engineering technology, and biomedical. Scopus is the world’s largest abstract and citation database for peer-reviewed literature. These three databases essentially cover all authoritative texts in English and Chinese, ensuring the data authenticity and research usefulness. The design method is a relatively broad concept that Jones [39] defined in his book Design Methods as procedures, techniques, aids, or tools for design. Such methods provide different types of activities that designers may use throughout the design process. Traditional design procedures, such as drawing, may be considered a design method, but since the 1950s, new procedures have emerged and are often grouped under “design methods”, which “attempt to make public the hitherto private thinking of the designer and to externalize the design process”. Therefore, we identified techniques, principles, strategies, methods, guidelines, and ideas as the key concepts of design methods. To ensure the comprehensiveness and accuracy of the sample data, after many search experiments, the final search term was set as (TS = (“the elderly” OR “old people” OR “the aged” OR “elderly people” OR “old adults” OR “senior citizens” OR “older adults” OR “seniors”) AND TS = (“design method” OR “design philosophy” OR “design principles” OR “design concept” OR “design guidelines” OR “design policy”)). To grasp the research results as comprehensively as possible, the time was set to all years. The search restrictions of Article, Proceedings Paper, and Book Chapter were added, and after the manual screening of non-conforming literature, 900 studies from Scopus and 177 from WoS were shown. To ensure the accuracy of data collection, the following situations were excluded from the retrieved literature: (1) design works, (2) information collected by magazines, (3) reported articles, such as personal interviews, exhibition consultation, conference news, and conference speeches, and (4) articles with incomplete literature and irrelevant to the research topics. Since most of the WoS studies were consistent with the results of the Scopus, 566 English studies were finally selected from W&S. CNKI was used for the Chinese research search, and there was no set time limit. After looking through research on the theme of “design methods for the elderly”, 655 papers published in the Chinese language from 2001 to 2021 were selected. The search date was 20 September 2021, and the selected total of 1221 references was used as the dataset for further analysis.

3.2. Data Processing

CiteSpace is a data visualization analysis software designed to conduct scientific analyses of the latent knowledge inherent in the literature [40]. The program can visually analyze scientific material, track research hotspots in the area, and identify research trends. Before creating the document map using the WoS text data format, the built-in CiteSpace data converter was used to preprocess the CNKI and W&S documents. To guarantee the accuracy of the findings, the W&S and CNKI data were filtered to remove duplicates after the format conversion.

3.3. Methodology

A comprehensive analysis of the dataset, including the annual distribution of the data set, co-occurrence of keywords, and discipline distribution, was conducted. The analysis of the annual distribution helped understand the development status of the subject or theme. Conversely, keyword analysis was done to reveal the key themes of the paper, popular keywords, and frontier knowledge of the entire field [41]. Co-occurrence analysis of the scientific fields cited in the research showed that the same text was distributed in different scientific fields. Triangulation was performed to cross-check the collection and collation of multiple sources materials, avoid the limitations of single-source materials, reduce bias or errors in manual coding, and ensure the scientific accuracy and precision of the results.

CiteSpace set the time threshold from 1975 to 2021 and selected one year as the time slice. The connection strength between studies was calculated based on cosine distance. The data of the 30 nodes with the highest frequency in each period were filtered to eliminate redundant information and to ensure the clarity of the map. After completing the threshold configuration and selecting institutions, keywords, categories, and countries in the target analysis function panel as the clustering basis, we used the automatic clustering function available in CiteSpace to draw a knowledge map [42].

4. Analysis of Literature from W&S

4.1. Overview of Studies on Design Methods for the Elderly from W&S

Figure 1 shows the first research report in W&S related to design methods for the elderly in 1975. In the early stages of research on this topic, this field did not attract widespread attention from international scholars, and there were few publications every year. Since 2007, this field has received increasing attention from scholars and experts, and the W&S literature on design methods for the elderly has gradually increased. Since 2021 was not yet over, there was no analytical value in discussing the volume of papers issued in 2021. The annual averages of 2010 and 2015 were lower than those of the previous years, with the most obvious decline in 2015 (approximately 27.1%), but growths were observed in the following years. The most obvious was in 2011, with the annual volume of papers increasing by 55.6% compared to that in 2010. This indicates that there is still a large scope for research in the field of design methods for the elderly.

By the end of December 2020, 72 articles on design methods for the elderly had been published, and related research is expected to continue growing. Research on design methods for the elderly is a multi-disciplinary problem, and thus it covers various methods for solving elderly issues. The important subtopics of W&S are listed in Table 1. Among the 566 papers, most of the papers belonged to the following fields: 274 from computer science, 188 from engineering, and 75 from social science, accounting for 48.41%, 33.22%, and 13.25% of the total number, respectively. Every subject is an important research field of W&S. Software product design, mechanical industry product design, and architecture are also important research directions of design methods for the elderly, which play important roles in their corresponding fields. The above-mentioned research directions guarantee the sustainability of assisted living for the elderly from the perspectives of home, architecture, and interface, prolong their independent living ability and promote the sustainability of their life and health.

Table 2 lists the important international studies related to design methods for the elderly. The most cited 10 articles mainly focus on three aspects: medical care, Internet usage, and life assistance. These three aspects ensure the sustainability of the life and health of the elderly and their adaptation to technological advancements. The main reason is that the monitoring and assistance of the physical condition of the elderly are particularly important for the elderly. Helping the elderly use the Internet is another important research topic given that using the Internet can significantly improve their physical and mental health, improve their subjective well-being and life satisfaction, and help them achieve healthy aging [43]. Three of the top 10 most cited documents were published in Conference on Human Factors in Computing Systems—Proceedings showing that it is an important platform for the related research.

4.2. Quantitative Analysis of the Studies on Design Methods for the Elderly from W&S

Research Hotspots

As shown in Figure 2, a hybrid network comprising terms from the 566 studies from W&S produced 12 major clusters (as detailed in Table 3). By evaluating and summarizing the terms associated with each cluster, we categorized the studies into four hot topics: aging, life assistance for the elderly, technology use for the elderly, and user experience for the elderly.

For the aging problem, we labeled the cluster “independent living”, “life”, “activities of daily living”, “social impact”, and “older driver”. Aging is an important factor that limits sustainable development, and the implementation of a human-centered sustainable development strategy requires a well-designed demographic environment. With the problem of population aging becoming increasingly prominent, a substantial elderly population has formed a considerable pension market. The medical security, equipment, and living aids for the elderly are also constantly improving, and the problem of aging has gradually attracted attention from researchers.

For the life assistance for the elderly, we labeled the clusters “assistant devices” and “barrier-free design”. In the rapid development of science and technology, the construction of simple and easy-to-use product interaction modes so that the elderly can use the product easily and happily, and the assistance and improvement in the quality of life of the elderly are topics of increasing importance for the scholars. As the elderly continue to age, their physical and mental health problems become highly prominent, which may introduce obstacles to their daily lives and eventually require their use of assisted living facilities that improve their health, living ability, and quality of life and help them achieve sustainable life and health.

For the technology use of the elderly, the clusters were labeled “assistive technology” and “Bayesian network”. To help the elderly adapt to the changes brought about by information technology, meet the needs of the elderly to use and adapt to the new technologies, and provide them with simple and convenient products, researchers continue to study the technical levels of products to promote a warmer, healthier, and more vibrant aging society and to actively contribute to a comprehensive, coordinated, and sustainable development of aging.

Finally, for the user experience of the elderly, we categorized the cluster as “ergonomics”, “interaction design”, and “human–machine interface”. With the popularity of the Internet, an increasing number of elderly people are beginning to use the Internet. In fact, in many situations, elderly people are forced to use the Internet. Therefore, the needs and habits of the elderly should be considered in the construction of Internet-based products, and the research on improving their user experience becomes increasingly important.

Further examination of the term co-occurrence graph revealed that human–computer interaction, ergonomics, and human engineering were all subgroups with a high degree of centrality, with centrality values of 0.11, 0.08, and 0.08, respectively. Additionally, the sub-clusters produced at the end of each cluster time axis in Figure 2 include topics such as technological adoption, user experience, cognitive load, health monitoring, body aids, hybrid reality, the Internet of Things, and mobile health. These keywords denote the cluster’s frontier themes. Most of these frontier themes are related to the sustainability of life and health of the elderly and their adaptation to technological advancements.

5. Analysis of the Literature from CNKI

5.1. Overview of Studies on Design Methods for the Elderly from CNKI

In 2001, the first CNKI article on the subject was published by Wang and Liu [54]. They combined the contents of the related disciplines, such as physiology, psychology, sociology, and environmental psychology of the elderly. Based on the characteristics of outdoor activities of the elderly, they discussed the related elements of outdoor activities and environmental quality and proposed the basic principles of outdoor environment design for the elderly to ensure their healthy life and sustainable development. Figure 3 shows that from 2001 to 2020, the number of studies on design methods for the elderly has shown rapid growth, with a significant decline in 2018, but a significant increase in 2019, reaching a peak of 126 in this year. The number of publications is expected to continue to increase in the future. The steady growth trend of the number of CNKI and W&S publications in this field has been similar over the past few years.

Table 4 shows the subject distribution of the research on design methods for the elderly in CNKI, indicating that product design is the main research topic of the CNKI publications. Among the 655 Chinese research samples, 40.31% of the studies were on product-design-related issues, and 50% were related to architectural design, landscape design, and interactive interface design.

The distribution of research directions was revealed by analyzing the most cited CNKI literature. Table 5 lists the 10 most cited studies, five of which discuss product design and development principles for the elderly, four discuss the aging housing and pension mode, and only one discusses environmental design. The economic, environmental, and social values of designs for the elderly were considered in a balanced manner from multiple perspectives. By integrating relevant economic, ecological, and social values, sustainable designs for the elderly can be realized. Among these 10 studies, three were from Architectural Journal, and two were from Packaging Engineering. These two journals are important platforms for related research.

5.2. Quantitative Analysis

Research Hotspots

Figure 4 depicts the co-occurrence of terms in CNKI literature over time. The 396-node hybrid network has twelve significant clusters (Table 6). It is summarized as follows: elderly population, design methods, barrier-free design, housing, and emotional needs of the elderly.

For the elderly population, the suitable cluster names were “the elderly” and “elderly population”. This topic is commonly seen in architectural design, construction of public facilities (shopping malls, hospitals, schools, etc.), and home environment decoration. Including the realization of barrier-free designs and the introduction of emergency systems, scholars have done significant research to meet the needs of the elderly life and travel and ensure their safety.

For the design methods for the elderly, the cluster names were “design strategy”, “design concept”, and “design principles”. In many aspects of residential spaces and products or public services for the elderly, scholars have proposed suitable design methods that help the elderly adapt to their environments, meet their needs in healthy aging, and achieve sustainable aging and environment.

For barrier-free design, the cluster name is “barrier-free design” and “barrier-free”. Using a barrier-free design throughout humanistic care as a core sustainable development concept may reflect the social development process of disadvantaged groups. Barrier-free design in a variety of public space environments, construction facilities, and equipment related to people’s clothing, food, housing, transportation, and other facilities must fully consider the usage needs of the elderly to ensure their safety and comfort. With the aging of society and an increasing number of serious contradictions, barrier-free design has been a topic of interest for scholars.

In terms of housing for the elderly, the cluster names were “architectural design” and “apartment for the elderly”. The construction of high energy-consuming public buildings increases the importance of reducing environmental hazards and achieving sustainable development. With the gradual decline in the physical function of the elderly, it becomes difficult for them to endure the drastic changes brought about by the environment. Therefore, the design of elderly housing fully considers the above situation and provides comfortable housing for the elderly by constantly improving the physical level of care and considering the psychological and emotional feelings of the elderly.

In terms of the emotional needs of the elderly, the cluster names were “user experience”, “hospitality design”, and “human–machine interface”. The researchers analyzed the psychological and emotional needs of the elderly, presented the characteristics and importance of meeting their emotional needs, and proposed a humanized design scheme to meet their physiological and psychological characteristics.

Smart home products, intellectualization, digital products, humanism, experience design, service design, communal facilities, and green building concept were the main sub clustering methods at the end of the clustering time axis, and they indicate the forefront of China’s current research on design methods for the elderly. Similarly, most of these frontier themes are related to the sustainability of life and health of the elderly and their adaptation to technological advancements. “Design principle” is the earliest term, which first appeared in 2001 with a centrality of 0.22.

6. Comparative Analysis of the Literature from W&S and CNKI

Based on the findings, the literature on design methods for the elderly appeared in 1975 in W&S, but it was not until 2007 that the international scholars started focusing on this topic. Since the first research on design methods for the elderly in CNKI was in 2001, this topic has attracted the attention of Chinese academia during the same period as W&S, and the number of related studies has increased over the years. The results showed that the research on design methods for the elderly had received increasing attention in recent years. According to the W&S literary distribution, China was the world’s second-biggest contributor, accounting for 18.79% of the total world research. However, the overall amount of Chinese literature on CNKI surpassed the total amount of papers in W&S, indicating that Chinese academics might have favored the Chinese academic platform.

Social science, computer science, and engineering were the three primary research fields of W&S. In comparison, over 90% of the studies in CNKI examined the design approaches for the elderly, focusing on product design, architectural design, landscape design, and interactive interface design.

The research emphases of W&S and CNKI were different. The aging problem, life assistance for the elderly, technology use for the elderly, and user experience for the elderly were the main research hotspots of W&S literature. Human–computer interaction and user interface were the common keywords. The main research hotspots of CNKI were the elderly population, design methods for the elderly, barrier-free design, housing for the elderly, and emotional needs of the elderly. Barrier-free design, product design, and pension building were the common keywords. To summarize, W&S research is more theoretical research, while CNKI research focuses on summarizing the methods from practice. Furthermore, although the frontier themes differ between W&S and CNKI, they are mostly related to the sustainability of life and health of the elderly and their adaptation to technological advancements.

7. Discussions

By collecting and categorizing the literature on design methods for the elderly in the W&S databases, as well as assessing the nationwide influence on the subject, we concluded that China was the second most significant country in this field, after the United States. Since the bulk of important research results published by Chinese academics is in the Chinese language, doing a literature search utilizing only the English databases may result in incomplete or one-sided conclusions. Therefore, using 566 English papers from W&S and 655 Chinese documents from CNKI as examples, this study analyzed the research state, development process, and future trend of design approaches for the elderly. On this basis, the frontier issues in research on geriatric design methods and future research directions are further discussed here.

Although research on the design approaches for the elderly in W&S dates back to 1975, this topic originally received little attention. Only after 2007 did the number of relevant studies begin to grow substantially. Between 2007 and 2020, the number of papers on W&S grew from 5 to 72, with a CAGR of 20.99%. Consequently, the global society progressively expanded its focus on elderly-friendly design approaches. CNKI released the first study on geriatric design techniques in 2001, but it did not get broad notice in China’s academic community until it gained worldwide attention. Between 2001 and 2007, the number of papers in CNKI grew irregularly, reaching a research zenith in 2019. Notably, although the number of CNKI studies has increased, the number of Chinese academics publishing studies on W&S has also increased, accounting for 18.79% of the entire literature. It demonstrates that, although Chinese academics continue to prioritize local platforms, they are increasingly focusing on international academic platforms.

The design approaches for the elderly entail multidisciplinary research. The primary areas of study in W&S studies included social sciences, computer sciences, and engineering. The CNKI studies were mostly conducted with a focus on design. Product design, architecture, and landscape design were the three fields with the most publications. Consequently, the studies of W&S and CNKI have distinct foci and complementarity, and academics should use both.

The W&S and CNKI research hotspots were both connected and distinct. The four main research areas of W&S studies were aging problems, life support for the aged, senior technological usage, and elderly user experience. The five research topics of CNKI studies included age-appropriate design, elderly design techniques, barrier-free design, senior housing, and elderly emotional requirements. Different research hotspots provide research guarantees for prolonging independent living and promoting the sustainable life and health of the elderly.

Researchers worldwide have expressed concerns about the research related to design techniques for the elderly population. Scholars worldwide have examined the product design, interactive interface, and emotional requirements of the elderly from a variety of perspectives, but their study objectives were not entirely consistent. W&S studies focused on the user experience of the elderly, whereas studies found in CNKI focused on their residential structures and product usage. Human–computer interaction and user interface were the most significant terms in W&S, whereas product design and pension architecture were the most important keywords in CNKI. W&S studies provided research guarantees for the sustainability of assisted living for the elderly in terms of housing, architecture, and interfaces to prolong their independent living and the sustainability of their life and health. Meanwhile, CNKI studies enhanced the sustainability of designs for the elderly by integrating relevant economic, ecological, and social values.

Given the scientific character and worldwide application of research on design methods for the elderly, we anticipate that global interest in this topic will continue to grow. Therefore, the question of “How should scholars approach the study of design approaches for the elderly?” arises. Researchers worldwide are interested in frontier problems, such as technological adoption, user experience, cognitive load, health monitoring, body aids, hybrid reality, the Internet of Things, mobile medicine, and apps, as evident from the W&S studies. Researchers in China are more interested in intelligent home goods, intellectualization, digital products, humanism, experience design, service design, communal facilities, and green building ideas for the elderly, as evident from the CNKI studies. To better serve the elderly fulfill their requirements, advances in science and technology are in the direction of becoming more intelligent and virtual. Therefore, product designers must build designs and services that are age-appropriate, with full functions and simple operations. The logical use of science and technology with an emphasis on the user experience of the elderly and the consideration of societal sustainability are major problems in this area and essential paths for future studies.

Traditional literature review methods rely on researchers to collect the literature, read it extensively, and summarize it manually. Literature collection is based on individual criteria, and with each researcher having different criteria, the literature data sources are also different; moreover, each researcher has limited time and energy. Different perspectives and cognitive styles may lead to different conclusions from different researchers analyzing the same literature within the limited literature data.

However, the integration of bibliometrics with visual knowledge maps enables researchers to conduct a more trustworthy literature assessment, allowing them to comprehend the growth and evolution of hotspots in a particular area completely and methodically. The subject terms generated by titles, abstracts, and keywords can be used for cluster analysis. The data samples collected in this study can reflect the advantages of scientometrics, and this type of analysis can be repeated among different researchers. As long as the standards are the same, the results must be the same. Currently, there is no comprehensive bibliometric study of the literature on design approaches for the elderly. This study collected and analyzed the authors, keywords, citations, and source journals of the literature in this field using visual measurement software to reflect the current research hotspots and development trends more intuitively and accurately, as well as provide ideas for future related research. Specifically, in light of the significant impact of Chinese academics in this area, whose texts were not included in official English databases but instead incorporated into an authoritative Chinese database, their similarities and differences were evaluated simultaneously. In comparison to other studies of literary analysis, Chinese academics conducted more thorough studies. The study findings indicated that although W&S and CNKI databases had comparable research patterns, there were significant variations in topic distribution and research hotspots. Therefore, researchers must consider papers in both the W&S and CNKI databases to understand the pattern and trend of research on design methods for the elderly.

8. Implications and Limitations of the Study

The findings of this study are beneficial at multiple levels. For practitioners, this study can improve their design efficiency and resource utilization to promote healthy and sustainable designs for the elderly. For design educators and researchers, this study provides reliable bibliometrics data and a visual knowledge map for literature review and helps researchers obtain information more clearly and intuitively. Finally, for consumers, this study supports the diffusion of design innovation centered on the elderly and promotes sustainable design development for the elderly.

To avoid misunderstandings and guide future investigations, the following two main limitations of this study must be focused on. First, although our data covered important articles in the field of design methods for the elderly, many relevant articles outside the three databases were not covered in the current study. Second, researchers have conducted various studies under the framework of sustainable development. User-centered design, universal design, design for all, design for aging, inclusive design, and barrier-free design are all footholds for sustainable aging. We need to work together to achieve harmony between the elderly and the environment in these footholds. Only in this way can sustainable design improve the well-being of society as a whole and contribute to its sustainable development.

9. Conclusions and Future Research

This study examined the state-of-the-art research, development process, and future trend of design approaches for the aged using a bibliometric methodology. We conducted a comprehensive review of the relevant literature from W&S and CNKI, as well as yearly network analysis of publication counts, subject distribution, highly cited research, and literature keywords. The most significant research platforms, topics, and hotspots were identified in this field, and the three databases were compared and assessed.

Simultaneously, this study demonstrated a CiteSpace-supported approach for in-depth and quantitative research on a worthwhile topic. In this case, a methodological contribution was provided with the example of design methods for the elderly. In contrast to a brief review of the existing literature, this methodology combines the field of design methods for the elderly with visualization, which shows that the research directions, research hotspots, and the frontiers of design methods for the elderly provide an excellent reference value for scientific research and design development. In addition, CiteSpace’s reference analysis can overcome the under-reading of literature common in traditional literature review methods, as their references adequately cover important information from key papers in a given field, even in the limited literature data.

There is still some room for improvement in this study in the future: Although CiteSpace was used for information visualization and quantitative analysis in the research field of design methods for the elderly, this study is only a preliminary work due to the increasingly severe global aging problem and the vigorous development of corresponding design methods. For future bibliometric research, it is suggested that, if the research contribution and influence of non-English-speaking countries are particularly significant in a particular field, scholars should also make an effort to analyze the authoritative literature in the local database to gain a better understanding of the global research frontier and development trend.

Author Contributions

Writing—original draft preparation, Y.L.; writing—review and editing, S.H.A.-R. and R.A.R.G.; supervision, S.H.A.-R. and R.A.R.G. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures and Tables

Table 1

Topic distribution of the studies on design methods for the elderly from W&S (Top 3).

No.	Topic	Quantity	Proportion
1	computer science	274	48.41%
2	engineering	188	33.22%
3	social sciences	75	13.25%

Table 2

Top 10 most cited studies on design methods for the elderly from W&S.

No.	Title	Author	Journal	CitationCount	Year
1	Proof of principle for epitope-focused vaccine design [44]	Correia et al.	Nature	272	2014
2	Full-body motion-based game interaction for older adults [45]	Gerling et al.	Conference on Human Factors in Computing Systems—Proceedings	269	2012
3	The domesticated robot: Design guidelines for assisting older adults to age in place [46]	Beer et al.	HRI’12—Proceedings of the 7th Annual ACM/IEEE International Conference on Human–Robot Interaction	177	2012
4	EL-E: An assistive mobile manipulator that autonomously fetches objects from flat surfaces [47]	Jain and Kemp	Autonomous Robots	121	2010
5	Desiring to be in touch in a changing communications landscape: Attitudes of older adults [48]	Lindley et al.	Conference on Human Factors in Computing Systems—Proceedings	114	2009
6	Healthcare in everyday life—designing healthcare services for daily life [49]	Ballegaard et al.	Conference on Human Factors in Computing Systems—Proceedings	113	2008
7	Evaluating websites for older adults: Adherence to ‘senior-friendly’ guidelines and end-user performance [50]	Hart et al.	Behaviour and Information Technology	108	2008
8	Design and control of an exoskeleton for the elderly and patients [51]	Kong and Jeon	IEEE/ASME Transactions on Mechatronics	105	2006
9	Research-derived web design guidelines for older people [52]	Kurniawan and Zaphiris	ASSETS 2005—The Seventh International ACM SIGACCESS Conference on Computers and Accessibility	101	2005
10	Increasing the usability of online information for older users: A case study in participatory design [53]	Ellis and Kurniawan	International Journal of Human–Computer Interaction	90	2000

Table 3

Keyword clustering table of the literature on design methods for the elderly from W&S.

Ordinal	Cluster Header	Main Cluster
1	“independent living”; “life”; “activities of daily living”; “social impact”; “older driver”	Female; aged; human; disability; mobile application; technology adoption; assistive technology; housing for elderly; health care; acceptance; user experience; multimedia services; universal design; artificial intelligence; computer science; user-centered design; active aging; website; online system; automobile manufacture; automobile ergonomics; quality function deployment
2	“assistant devices”; “barrier-free design”	Computer-aided design; robot; robotics; aging in place; agricultural robot; health monitoring; human–robot interaction; physically assistive device; smartphone; controlled study; exercise equipment; caster walker; human rehabilitation engineering
3	“assistive technology”; “Bayesian network”	Information technology; interaction design; interface design; nursing; Internet of Things; mixed reality; IoT; usability; product design; computer system; human factor; tactile interface; design strategy; behavior research; mobile health
4	“ergonomics”;“interaction design”;“human–machine interface”	User interface; user need; human–computer interaction; accessibility; hci; cognitive load; knowledge management; human engineering; inclusive design; communication; virtual environment; ergonomics; co-design; long term care; application program; health care system

Table 4

Discipline distribution of the studies on design methods for the elderly from CNKI (top 3).

No.	Topic	Quantity	Proportion
1	Product design	264	40.31%
2	Architectural design	204	31.15%
3	Landscape design	88	13.44%

Table 5

Top 10 most cited studies on design methods for the elderly from CNKI.

No.	Title	Author	Journal	CitationCount	Year
1	Research on outdoor environment of elderly people	Wang and Liu	Journal of Wuhan University (Engineering Edition)	92	2001
2	“Universal Design” Concept and Its Enlightenment to Housing Construction [55]	Yang and Liu	Architecture Journal	83	2004
3	Behavior analysis of the elderly and barrier-free design strategies of products [56]	Wang	Journal of Beijing University of Technology (Social Science Edition)	78	2009
4	Research on the Principles of Product Design and Development for the Elderly [57]	Zhou	Packaging Engineering	63	2008
5	Non-blood relationship multi-generational residence—The case and enlightenment of Germany’s new social mutual assistance pension model [58]	Qiao and Cai	Architecture Journal	62	2014
6	Analysis on the principles of design and development of products suitable for aging [59]	Wang et al.	Electromechanical product development and innovation	57	2006
7	Comparison of the design of housing suitability for old age in China, the United States and Japan [60]	Zhang et al.	Architecture Journal	54	2013
8	Humanized design of products for the elderly [61]	Wang et al.	Forestry Labor Safety	47	2006
9	Product design principles based on phased research on the elderly [62]	Wang and Jiang	Packaging Engineering	42	2011
10	Thinking problems related to architectural design of facilities for the elderly [63]	Wei and Yu	Huazhong Construction	38	2011

Table 6

Keyword clustering table of the literature on design methods for the elderly from CNKI.

Ordinal	Cluster Header	Main Cluster
1	“the elderly” and “elderly population”	The elderly; product development activities; requirement analysis; modularization; usage requirement; people-oriented; therapeutic; aging; Internet of Things; medical center
2	“design strategy”, “design concept”, and “design principles”	Outdoor activity space; design strategy; empty nester; use–value; caring design; product features; intelligent product; products for the elderly; functionality; security
3	“barrier-free design” and “barrier-free”	Barrier-free environment; hospital architectural design; barrier-free facilities; pension facilities; landscape design
4	“architectural design” and “apartment for the elderly”	Design for the senior apartment; architectural design; universal design; planning and design; pension building; humanism; functional characteristics; home care; use function green building concept
5	“user experience”, “hospitality design”, and “human–machine interface”	General design; accessories; industrial design leisure products; usage habit; technology products; emotional needs; interactive

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