*3.4. Questionnaire Survey Results*

A total of 120 copies of questionnaires were collected from 60 pairs of grandparents and grandchildren. Each questionnaire included questions about the participant's basic data, as well as the evaluations of the two indicators of the GPIC scale and the elderly's attitude scale. The basic data are shown in Table 8, in which it can be seen that 70% of the participants had never experienced VR before, while 30% of the participants had previously used a VR system.


**Table 8.** Basic data of the participants obtained in the questionnaire survey.

In addition, among the 120 collected questionnaires, 114 copies from 57 pairs were valid, and 6 from 3 pairs were invalid. Each questionnaire also included questions about and the evaluations of the two indicators of the GPIC scale and the elderly's attitude scale, with the former indicator involving both the elderly and the children, and the latter concerning only the children. The questions of the two indicators are shown in the second column of Table 9, with questions S1–S9 being related to the first indicator, and T1–T15 related to the second. Some statistics of the collected feedback data of the Likert 5-point scale of the two indicators are listed in Tables 9 and 10; these were analyzed in detail from several points of view, as described in the following.

**Table 9.** Questions and average statistics of the data of the two indicators of the GPIC scale and the elderly's attitude scale obtained in the questionnaire survey.



**Table 10.** Detailed statistics of the data of the two indicators of the GPIC scale and the elderly's attitude scale obtained in the questionnaire survey.

Table 9 includes questions about the children's feelings toward the elderly's behaviors in the system-experiencing process that were filled out by the participating children. The standard deviations of T6, T10, and T13 in the table are greater than 1, which reflect the children's divergent feelings about their grandparents' willingness to learn new things or interests in acquiring new knowledge, as well as their cognition of the elderly's passiveness in these activities.

### 3.4.1. Designing Processes for Testing the Properties of the Collected Data

In this study, the SPSS and AMOS software packages were used to analyze the collected questionnaire data. A series of tests were conducted to verify the properties of the collected data to ensure that the data could be analyzed to evaluate the effectiveness of the proposed system for intergenerational learning. The data properties and the methods adopted to verify them are listed in the following, with the details described later in this section.


5. Validity of the collected questionnaire data—verified by the parameter values yielded by the EFA and CFA processes.

### 3.4.2. Testing the Adequacy of the Collected Data

To evaluate the adequacy of the collected questionnaire data listed in Tables 9 and 10, the Kaiser–Meyer–Olkin (KMO) test and the Bartlett's test of sphericity were adopted in this study [66–71]. The KMO measure is a statistic used to indicate the proportion of variance among the variables that may possibly be caused by certain factors underlying the variables. The KMO test returns measure values in the range of 0 to 1, and Kaiser [69] assigned the returned values into six categories: (1) unacceptable—0.00 to 0.49; (2) miserable—0.50 to 0.59; (3) mediocre—0.60 to 0.69; (4) middling—0.70 to 0.79; (5) meritorious—0.80 to 0.89; and (6) marvelous—0.90 to 1.00. A KMO measure value larger than the threshold value of 0.50 is usually regarded to pass the test [66,67].

Additionally, the Bartlett's test of sphericity is employed to test the hypothesis that the correlation matrix of the data variables is an identity matrix, which indicates that the variables are unrelated. A significance value of the test result smaller than the threshold value of 0.05 is usually considered as acceptable to reject the hypothesis, or equivalently, to pass the test [67,68]. When both of the two tests are passed, the data variables are usually said to be *adequately related* for further structure analysis [70].

By using the collected questionnaire data and their statistics shown in Tables 9 and 10, the KMO measure values and the significance values of the Bartlett's test for the two indicators were computed by the SPSS, and are listed in Table 11. It can be seen in the table that for either indicator, the KMO measure value is larger than the threshold of 0.5 and the significance value of the Bartlett test is smaller than the threshold 0.05. Consequently, it was concluded that the datasets of both indicators of the GPIC Scale and the Elderly's Attitude Scale were *adequately related* for further *structure analysis*, as described next.


**Table 11.** The measured values of the KMO test and the significance values of Bartlett's test of the data collected for the GPIC scale and the elderly's attitude scale.

3.4.3. Finding the Latent Dimensions (Scales) of the Questions from the Collected Data

With the adequacy of the questionnaire data being verified as described above, the SPSS package was used further to perform an exploratory factor analysis (EFA) using a principal component analysis. In addition, the varimax method with Kaiser normalization was employed to find suitable latent dimensions (scales) for the questions with the collected data as inputs. The details of the results are listed in Tables 12 and 13. It was found accordingly that the nine questions (S1–S9) of the first indicator, global perceptions of intergenerational communication (GPIC), could be divided into three groups under the question dimensions (scales) of *accommodation*, *nonaccommodation*, and *avoidance*, respectively. The 15 questions (T1–T15) of the second indicator, the elderly's attitude, could be divided into three groups as well under the question dimensions (scales) of *psychological cognition*, *social engagement*, and *life experience*, respectively. The results of such latent dimension (scale) findings, with some statistics of the data of the Likert scale included, are shown integrally in Table 14.


**Table 12.** Rotated component matrix of the indicator of GPIC.

Extraction method: principal component analysis. Rotation method: varimax with Kaiser normalization; rotation converged in 5 iterations.



**Table 14.** Analysis of the question dimensions (scales) of GPIC and the elderly's attitude by SPSS.



### **Table 14.** *Cont.*

3.4.4. Verifying the Reliability of the Collected Data Using the Cronbach's α Coefficients

Reliability is about the consistency of a measured dataset despite the repeated times [72]. In this study, the Cronbach's α coefficient [73,74] yielded by the EFA mentioned previously was adopted to analyze the reliability of the collected questionnaire data. It is known that the closer the Cronbach's α coefficient of a dataset of a scale is to the extreme value of 1.0, the greater the reliability of the dataset (regarded as variables) is. Based on Gildford [75], the following rules may be used to judge the degree of reliability of a dataset:

α ≤ 0.35 — unreliable

0.35 ≤ α < 0.70 — reliable

α ≥ 0.70 — highly reliable

where α is the Cronbach's α coefficient value of the dataset.

The Cronbach's α coefficient values of the six question dimensions (scales) and those of the two indicators are shown integrally in Table 15. It can be seen in the table that all the Cronbach's α coefficient values are in the range of 0.35 to 0.70 or even larger, meaning that the collected questionnaire dataset of each question dimension, as well as those of each indicator are reliable.


*Sustainability* **2022**, *14*, x FOR PEER REVIEW 33 of 45

**Table 15.** Collection of the data of the indicators of GPIC and the elderly's attitudes and the Cronbach's α coefficients of the six question dimensions of the two indicators. 3.4.5. Verification of the Applicability of the Structural Model Established with the

3.4.5. Verification of the Applicability of the Structural Model Established with the Question Dimensions (scales) for each indicator show the fact that the structure model set up by the question dimensions (scales) of the indicator is of a reasonably good fit to the collected questionnaire data [77–

integrally in Table 16. Accordingly, the index values of χ2/df, gfi, cfi, and RMSEA yielded

Before proving the validity of the collected questionnaire data, the suitability of the structure model set up by the question dimensions (scales) need be verified [76]. For this purpose, the confirmatory factor analysis (CFA) process using the AMOS package was applied on the collected questionnaire data, yielding two three-scale structure-model graphs, as shown in Figure 17. Moreover, a list of structure-model fit indices was yielded by the CFA for each indicator, including the degrees of freedom (df), the chi-square (χ 2 ) statistics, the ratio of χ <sup>2</sup>/df, the adjusted goodness-of-fit index (gfi), the comparative fit index (cfi), and the root-mean-square error of approximation (RMSEA), as shown integrally in Table 16. Accordingly, the index values of χ <sup>2</sup>/df, gfi, cfi, and RMSEA yielded for each indicator show the fact that the structure model set up by the question dimensions (scales) of the indicator is of a reasonably good fit to the collected questionnaire data [77–81]. 81]. **Table 16.** Fitness indexes of the structural models of the two indicators of GPIC and the elderly's attitudes generated through CFA. **Scale df χ2/ χ2/df agfi cfi RMSEA RMSEA (90% CI) LO HI**  GPIC Scale 24 60.112 2.505 0.810 0.941 0.115 0.079 0.152 Elderly's Attitude Scale 74 102.299 1.382 0.727 0.968 0.830 0.037 0.101 Meanings of symbols—df: degree of freedom; gfi: goodness-of-fit index; agfi: average gfi; cfi: comparative fit index; RMSEA: root-mean-square error of approximation; CI: confidence interval; LO: low; HI: high.

**Figure 17.** Results of confirmatory factor analysis (CFA) using the AMOS package. (**a**) Diagram of the three-scale structural model of the GPIC indicator (FS1: accommodation; FS2: nonaccommodation; FB3: avoidance) generated through CFA; (**b**) diagram of the three-scale structural model of the elderly's attitude indicator (FT1: psychological cognition; FT2: social interaction; FT3: life experience) generated through CFA. **Figure 17.** Results of confirmatory factor analysis (CFA) using the AMOS package. (**a**) Diagram of the three-scale structural model of the GPIC indicator (FS1: accommodation; FS2: nonaccommodation; FB3: avoidance) generated through CFA; (**b**) diagram of the three-scale structural model of the elderly's attitude indicator (FT1: psychological cognition; FT2: social interaction; FT3: life experience) generated through CFA.

With the model structures of the two indicators both being proved to fit reasonably to the collected questionnaire data, it was proper to analyze further the validity of the **Table 16.** Fitness indexes of the structural models of the two indicators of GPIC and the elderly's attitudes generated through CFA.


3.4.6. Verification of the Validity of the Collected Questionnaire Data

Meanings of symbols—df: degree of freedom; gfi: goodness-of-fit index; agfi: average gfi; cfi: comparative fit index; RMSEA: root-mean-square error of approximation; CI: confidence interval; LO: low; HI: high.

### 3.4.6. Verification of the Validity of the Collected Questionnaire Data

With the model structures of the two indicators both being proved to fit reasonably to the collected questionnaire data, it was proper to analyze further the validity of the data. It can be seen from the three-scale structure model shown in Figure 17 that all the factor-loading values (also called standardized regression weights) with respect to the scales (appearing on the paths of the scales FS1–FS3 and FT1–FT3 to the questions S1–S9 and T1–T15, respectively) are all larger than the threshold of 0.5. This indicates that the construct validity of the model was verified. This fact can also be proved by the construct validity values of all the scales of the two indicators of GPIC and the elderly's attitudes yielded by the EFA process mentioned above, because such values, as listed in Table 17, can be observed to all be larger than the threshold value of 0.6 [82,83]. That is, the construct validity of the collected questionnaire data of the indicator of system usability is proven.

**Table 17.** Valid values of the question dimensions (scales) of the two indicators of GPIC and elderly's attitudes generated through CFA.


3.4.7. Summary of Analyses Based on the Content of the Collected Questionnaire Data

It can be concluded from the above discussions that the questionnaire data collected from the participants regarding the two indicators of GPIC and the elderly's attitudes are both reliable and valid for uses in further analyses of the data contents, which lead to the following conclusions.

(A) Analysis of the Indicator of GPIC

The overall feedback on the questionnaire regarding the evaluation of GPIC was positive. As shown in the upper part of Table 10, the average percentage of agreement was 80.9%, indicating that the participants felt good about the communication between grandparents and grandchildren in the experiences of using the proposed system. Furthermore, McCann and Keaton's GPIC scale [61] consists of two perspectives for the survey data collected in this study: "perception of others' communication" and "perception of one's communication". The former perspective was divided into the dimensions of accommodation and nonaccommodation in this study. Accommodation refers to a participant's perception that the other participant is friendly and kind during the interaction. Meanwhile, nonaccommodation referred to a participant's perception that the other is more competent during the interaction and can recognize their advantages. The other perspective, "perception of one's communication," has only one dimension—avoidance. Avoidance refers to a subject making a concession for some reason or in some circumstances when interacting with others.

The average score of S1, S2, S3, S4, and S5 in the nine questions on the indicator of GPIC was higher than 4.17, indicating that more than 80% of the participants approved of the intergenerational communication during the interaction. However, the score data show in the meantime that the awareness of other people was obviously higher than self-awareness, with a sense of friendliness and intimacy. In addition, as seen in Tables 9 and 10, the question S7 yields a lower score with a standard deviation value larger than one because a small number of users gave it just one point. This fact indicates that the users had different views on compromising in the interaction process using the proposed system.

More generally, based on the data-analysis results shown in Tables 9 and 10 regarding the indicator of GPIC, the following conclusions were drawn:


Most of the questions received positive feedback regarding the elderly's attitudes. As shown in the second part of Table 10, the average agreement rate was 82.7%, indicating a good overall evaluation of the interaction between the children and the elderly.

More specifically, the average scores of 9 of the 15 questions (T1, T3, T7, T8, T9, T10, T12, T14, and T15) were above 4.33. The second part of Table 10 shows that the average agreement rate was 82.7%, and according to Table 9, the children were seen to think that the elderly held positive attitudes. The highest score, T8, indicated that the children psychologically believed their grandparents were trustworthy. The two questions with lower scores are T13 and T6. Based on the data analysis of the elderly's attitudes felt by the children, the following conclusions were drawn:


3.4.8. Evaluation of System Effectiveness from the Perspectives of GPIC and the Elderly's Attitudes

In the evaluation of the system effectiveness from the perspective of GPIC, the average scores of the three dimensions of "accommodation", "nonaccommodation", and "avoidance" are larger than four, and the agreement rates (including the rates of "strongly agree" plus "agree") are greater than 85%, as shown in Tables 18 and 19, which were computed using Tables 9 and 10. In addition, the average scores range from 4.02 to 4.35, all of which are greater than 4. These results indicate that grandparents and grandchildren performed well in communication during the interaction.

**Table 18.** Evaluation of the average scores of GPIC and the elderly's attitudes from the perspectives of the two indicators.



**Table 19.** Evaluation of the percentages of GPIC and the elderly's attitudes from the perspectives of the two indicators.

Meanwhile, in the evaluation of the system effectiveness from the perspective of the elderly's attitudes, the average scores of the three dimensions of "psychological cognition", "social interpersonal participation", and "life experience" are larger than four, and the agreement rates (including the rates of "strongly agree" plus "agree") are greater than 80%, as shown in Tables 18 and 19. In addition, the average scores range from 4.32 to 4.34, all of which are greater than 4. These results indicate that the elderly showed good attitudes during the interaction as felt by the children.

It is noteworthy that the average score for the elderly's attitudes is 4.33, higher than that of GPIC, which is 4.17. This fact indicates that the children had positive psychological and cognitive experiences during the interaction with the elderly, and that the psychological cognition and life experiences of the elderly were felt as positive attitudes by the children.

### *3.5. Analysis of Interviews with Participants*

Based on Verplank's interaction design principles [65], in this study the participants' feelings about their experiences when using the proposed system were investigated via interviews with the participants. The interviews mainly focused on the aspects of system operation (labeled as DO), feeling of experiencing the system (labeled as FEEL), and communication of emotion and experience (labeled as KNOW). For DO, the questions for the participants included the aspects of system operation, interface, and design difficulty. For FEEL, the problem design was based on the participants' feelings during and after the activities, as well as other related thoughts. Lastly, the part of KNOW involved the investigation of the participants' emotional communication and inheritance of relevant memories after experiencing the system, which was also the main design purpose of this study's prototype system. After conducting the intergenerational activities and the questionnaire survey, 10 users representing five pairs of grandparents and grandchildren were randomly selected for interviews. During the interview procedure, their responses were recorded using audio recorders and in writing. The participants' responses are summarized in Table 20.

According to the results of interviews with the participants listed in Table 20, most of them gave positive feedback on the two aspects of feeling of experiencing the system (FEEL) and communication of emotion and experience (KNOW). For the aspect of system operation (DO), the participants gave many suggestions, such as making slight adjustments to the gestures, providing a greater variety of images on the screen, and making the overall operation easier to understand. In addition, the participants who had experience in manipulating puppets were faster at playing with the puppets in the VR environment. In more detail, the conclusions that are drawn based on the interview results shown in Table 20 are the following.


### **Table 20.** Record data of interviews with participants.

	- (a) After playing the drums and manipulating the puppets with VR gestures, participants found the operations of the gong and the drum more intuitive and easier to understand.
	- (b) Most participants were not puppeteers, and gestures that were too professional were not easy for those inexperienced to perform.
	- (a) The young participants preferred interactions with more sound and light effects or with more variations.
	- (b) The children preferred operating the gong and the drum to performing VR actions.
	- (a) Older experienced participants learned puppetry more quickly than those without puppetry experiences, and they could impart to their grandchildren more knowledge about puppetry.
	- (b) In the intergenerational learning activities, the grandparents and grandchildren would increase the exchange of mutual learning experiences.

Furthermore, usability is an important evaluation item of an interactive system. Using the content of Table 20 regarding the aspect of System Operation (DO), the following is a short summary of the usability related to our research.


### *3.6. Summary of Experimental Results*

The major research findings of this study drawn from the above analysis results are listed in Table 21, and are organized from the perspectives of three previously published studies: (a) McCann and Giles [61], with the perspective of global perceptions of intergenerational communication (GPIC); (b) Lu and Kao [62], with the perspective of the elderly's attitude scale; and (c) Verplank [65], with the perspective of interviews with system participants.


**Table 21.** Summary of the major research findings of this study.

### **4. Discussions**

With the advent of aging societies and changes in family structures, intergenerational learning has become increasingly important in the current era. On the other hand, fast technology development has become the trend of the future in the 21st century, which makes integrating technologies into conventional intergenerational activities, as well as group learning or education, a long-term issue worthy of serious consideration. For example, Kyrpychenko et al. [27] proposed a good structure of communicative competence for teaching a foreign language to higher education students, and Kuzminykh et al. [28] proposed self-education and group-education approaches to the development of teaching competence. These diverse research directions and results further highlight the importance of the intergenerational learning issue investigated in this study, and offer useful insights for developing the system design principles of this study.

It was the main focus of this study to educate people of the older generation who were unfamiliar with fast-developing technologies. The aim was mainly to make technology more acceptable to them to narrow the gap between the young and the old. Therefore, a novel learning system was proposed in this study, with traditional puppetry being introduced as the theme, based on the life experiences of the older generation. By introducing digital technology into intergenerational learning and applying VR and TUIs in the learning activities, the two different generations could increase their communication and interaction, thereby achieving emotional exchange and the sharing of experiences. More findings of facts in this research are elaborated in the following.

### *4.1. Findings of System-Development Principles*

In this study, different subjects and activities based on the literature related to intergenerational activities were reviewed. In addition, existing cases on introducing intergenerational learning and VR technology to the older generation were surveyed. After deep discussions with invited experts, four design principles for the system development of VR-based intergenerational learning were created:


The prototype system developed in this study was based on the experts' advice and the above-mentioned design principles. After many tests and modifications, a new intergenerational learning system was constructed that was familiar to both generations and allowed them to promote emotion exchange.

### *4.2. Findings from Questionnaire Survey Results*

The questionnaire data collected from the participants who experienced the prototype system were analyzed by SPSS and AMOS, and the results showed that the data of the two indicators, GPIC and the elderly's attitudes, were reliable and valid for further evaluation of the system's effectiveness. The average values of the data of the two indicators are both larger than 4 points on a 5-point Likert scale, indicating that the participants' attitudes toward each other in the process of experiencing the intergenerational learning activities provided by the proposed system are relatively positive. In more detail, the following conclusions were drawn from the results of the questionnaire data analyses and the interviews with the participants:


### *4.3. Findings about Effectiveness of Technology-Based Intergenerational Learning*

In this study, the new technologies of VR and TUIs were used as the interfacing techniques of the proposed system for intergenerational learning. Such new technologies were adopted with the aim of arousing the interests of the two generations in the learning activities, and the data analyses of the questionnaire survey of the participants' opinions showed that this aim was achieved by the proposed system. More findings of facts about the effectiveness of the system are elaborated in the following.

(1) Intergenerational learning activities featuring VR and TUIs can encourage the young to participate in the learning activities

Based on the interviews with participants and the observation of their experiences, most children would step toward, pick up, stare at, and study the head-mounted display, and say they want to have a try. Some children told the interviewer that they wondered what was in the VR, showing that the introduction of VR and gesture manipulations could indeed arouse the willingness of the younger generation to participate.

(2) The VR-based interaction system with the two generations' shared experiences had positive effects on the emotional communication between the two generations

According to the results of the questionnaire survey and interviews with the participants, most users gave positive comments on the proposed interactive system after experiencing it, and both generations felt happy and interested in their interactions and experiences. In addition, both generations showed positive attitudes toward each other, consistent with the findings of Souza and Grundy [6]. Through intergenerational interactions, the elderly could acquire self-confidence and positive attitudes, while the young generation could improve their self-value and obtain happiness, conducive to the accumulation of social capital of human resources and relationships.

(3) Themes familiar to the older generation can enhance their willingness to adopt hightech products

Zajicek [21] found that one of the reasons elderly people reject high-tech products is the fear of damaging them in the process of learning. However, if the products are associated with the living environment of the older generation or are something with which they are familiar, they would be less anxious and more willing to enjoy high-tech products.

(4) By integrating VR into intergenerational learning activities, the two generations acquire more opportunities to learn and understand each other

The two generations guided each other in following instructions; for instance, in playing the drum or making the gestures. According to some interviewees, after participating in the activities, some elderly people shared the stories of the glove puppetry characters with their children. Similarly, several of the elderly reported that they had learned cartoon and game characters from some young participants, indicating that both generations have much more to talk about.

(5) Better perceptual experiences in feeling the effects of sensors, such as sound, animation, and various special effects, can improve the two generations' immersion in the system-experiencing process

It was found in the interviews that the users may have been less immersed in the activities due to certain problems occurring with the system, such as unclear screen tips, monotonous pictures, and unfamiliarity with the gestures. According to the participants' comments, it was known that if such problems could be solved, the activities would be thought to be more entertaining and interesting, and the users would immerse themselves in the activities more deeply.

### **5. Conclusions**

### *5.1. Summary of Major Contributions Made by This Study*

In this study, through the use of human-interfacing technologies, it was aimed to introduce innovative interactions into conventional intergenerational learning activities. An intergenerational learning system called "Recall the Play" was constructed. The architecture of the system was based on the technologies of VR and TUIs. The users' opinions obtained from the questionnaire surveys and interviews showed that emotional communication and experience inheritance between the two generations could be effectively promoted by integrating VR and TUIs into the learning process. In addition, appropriate intergenerational learning activities with the two generations each having dominant roles were designed and tested. The design was appropriate for the two generations, and was based on literature surveys related to intergenerational learning, as well as the interview comments given by experts before the activities were developed. Finally, human-interfacing hardware, including gesture detection, sound sensing, and VR, as well as software algorithms implementing an interactive game of traditional glove puppetry, were successfully integrated to construct the proposed intergenerational learning system. This integrated experience of system and game development can be used as a reference for future research in related fields.

### *5.2. Suggestions for Future Studies*

The intergenerational learning system developed in this study is in its infancy. Based on the research results obtained using this system, for future research on intergenerational learning, more appropriate designs with better interfacing effects may be considered to make users more focused on and immersed in the learning activity. This may be achieved by improving the fluency of animation, the richness of sound effects, and the vividness of system feedback. Secondly, learning activity themes other than puppetry, such as recreation, education, public service, health care, and individual development, as mentioned by Ames and Youatt [4], may be considered for future studies. In addition, it is also worth studying constructions of systems and related learning activities for more generations with different backgrounds.

In addition, the entire formal experimental procedure was assumed to be 30 min, and the time for experiencing the intergenerational activity was set to be 10 min. It is suggested that future extensions of this study be designed to contain a richer story script, and allow for a longer activity-experiencing time with a more gorgeous background environment for use by a wider range of generations, instead of being limited to the two generations of grandparents and grandchildren. The musical instruments utilized backstage also may be expanded to include wooden hand boards, cymbals, suonas, etc., which will arouse the interests of users involved in the game activity to a greater degree. To implement this, the sound-sensing technology used in the proposed system must be upgraded to include frequency sensing in addition to volume sensing, in order to differentiate the input sounds of the musical instrument played by the user backstage.

**Author Contributions:** Conceptualization, C.-M.W. and C.-H.S.; Methodology, C.-M.W. and C.-H.S.; Validation, C.-M.W. and C.-H.S.; Formal Analysis, C.-M.W. and C.-H.S.; Investigation, C.-H.S. and C.-E.H.; Data Curation, C.-H.S.; Writing—Original Draft Preparation, C.-M.W., C.-H.S. and C.-E.H.; Writing—Review and Editing, C.-M.W. and C.-H.S.; Visualization, C.-H.S. and C.-E.H.; Supervision, C.-M.W.; Project Administration, C.-M.W. 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:** Informed consent was obtained from all subjects involved in the study.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.

**Acknowledgments:** The authors would like to thank Shih-Mo Tseng from the Design Institute of Yunlin University of Science and Technology for setting up the show venue during the exhibition of the system constructed in this study to the public. Thanks are also due to the director of the Chang-Tai Older People Care Center at Douliu Township of the Yunlin LOHAS Service Group, Yi-Shan Kao, for her offering of space in the center to carry out the field experiments of this study. Furthermore, we also want to express our gratitude to president of the Puppets' House in Dounan, Yi-Sha Hsu, for her offering of space to carry out the field experiments. Finally, we would like to thank Chief Chia-Wei Chang of the Bald Pine Forest in Nantou for his offering of space to carry out the field experiments.

**Conflicts of Interest:** The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
