Keywords

1 Introduction

The world has gradually entered the hyper-aged society, and the daily necessities of elderly people are highly valued. Studies showed that the physical, psychological and learning situation of the elderly tended to be slow, their memory is degenerating and learning is easily disturbed (Wu 1999). Industrial Economics & Knowledge Center (IEK) of ITRI, Taiwan (2015) used “technology life” and “live independently” two indicators to classify Chinese elderly into four groups: Enlightened, more capable of accepting new technology in daily life and think they can live independently; Independents, not eager to use new technology in daily life but support for living independently; Fashionables, support using new technology but life is relatively independent and needs assistance; and Conservatives, stereotyped elderly generally not independent and low use of new technology. This categorization echoed Murata’s (2015) claim “elderly industry is ‘non-massive’ market, is a collection of various micro markets instead”.

In “Attractive product planning for mature market”, prof. Hirashima (1991) mentioned “Products of the new era must enrich the hearts of consumers and make users feel happy”. He further visualized with pictures showing the match of the attractive factor between planned and achieved. Therefore, Kansei needs of elderly people must be studied and their daily necessities should also be well designed to meet their Kansei preferences.

Consisting of 24 sets of adjectives describing personality traits, DISC personality test categorizes personality into four groups as: Dominance, Influence, Steadiness, and Compliance. Each set of adjectives were selected based on the four (D, I, S, C) measurement dimensions and some interference dimensions. Subjects were asked to pick the most suitable and the most unsuitable adjectives for themselves. DISC theory has been broadly used for human behavior classification, and more widely used in self-awareness, interpersonal interaction, and business marketing capabilities improvement (Chang 2015).

Based on the theory of Kansei Engineering, this study conducted research and analysis through experiments and in-depth interviews to explore the use of functional shoes for senior citizens. Through the Likert scale, synesthesia experiment, and quantification theory type I, the imagery evaluation of the functional shoes for the elderly was constructed and made possible to provide reference for the design of the functional goods for the elderly in the future.

The purposes of this study included: (1) identifying the specific design components of functional shoes that affect the psychological feeling of the elderly, and establishing their weights; (2) exploring the Kansei evaluation difference between single sense and multi-senses while using the functional shoes; and (3) exploring the preference on materials and colors of the functional shoes.

2 Methods

2.1 Participants

Total of 30 elderly were invited to participate the experiment. All of them have the experience of wearing functional shoes. Basic data of the participants include gender, age, education level and the DISC personality. Among them, 10 out of 30 were male (33%), female 20 (67%). On age, 14 out of 30 were between 65 and 69 (47%), 9 between 70 and 74 (30%), 5 between 75 and 79 (17%), 1 between 80 and 84 (3%), and 1 above 85 (3%). On education level, 21 (70%) with high school and below, 8 (27%) with junior college and only 1 (3%) has college education. As for the DISC personality, 11 (37%) of Dominance, 10 (33%) of Influence, 5 (17%) of Steadiness, while 4 (13%) were of Compliance (as shown in Table 1).

Table 1. Participant demographics (n = 30).
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The experiment was conducted during 21 April and 20 June of 2018 (Fig. 1).

Fig. 1.
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Photos show the participants during experiment

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2.2 Experimental Materials

The sample functional shoes consist of 8 components, namely: shoe body, shoe head, sole, midsole, heel sheath, shoe mouth, tie free, and insole (as shown in Fig. 2). The most important parts of frequently chosen shoes were identified for the purpose of Kansei evaluation on both single sensory and synesthesia experiment. Two most significant parts were chosen as the control factors: “Shoe Body” and “Insole”.

Fig. 2.
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Major parts of the elderly functional shoes

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2.3 Procedure and Tasks Design

The research process was divided into four stages: (1) choosing 6 Kansei words to be used in the visual, tactile and synesthesia experiments based on the results of the earlier study; (2) collecting and classifying the visual and tactile test elements of the functional shoes to be used as samples in the visual, tactile and synesthesia experiments; (3) Kansei experiment for the elderly on different DISC personality; (4) the analysis and discussion of the results for different DISC personality.

3 Results and Discussion

3.1 Selection of the Kansei Words

Following the earlier study, highly involved elderly were interviewed with evaluation grid method to conclude the final 6 adjectives, namely: “relieved”, “convenient”, “comfortable”, “professional”, “noble”, and “delicate”.

3.2 Selection of Functional Shoe Samples

The color and material are the two major options for shoe body. 13 colors of shoe body were popular on the markets and websites where the elderly can see and chosen from, include: red, orange, yellow, green, navy, purple, khaki, brick red, pink, white, gray, black, and florid. Color cards were printed in 20 cm by 13 cm for the visual Kansei evaluation experiment (Table 2). Total of 7 materials of real shoes were used for both single sensory (tactile and visual) and synesthesia experiment (Table 3). The size and numbering of each real shoes were paired randomly by computer.

Table 2. Color samples of shoe body
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Table 3. Material samples of shoe body
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As for the insole, material is the major option. Same selection process as above was made. Total of 7 materials were used for both single sensory (tactile and visual) and synesthesia experiment (Table 4). The numbering of each real insole was randomly decided by computer.

Table 4. Material samples of insole
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3.3 Items and Categories of the Experimental Samples

There were 2 items for tactile experiment, namely “shoe body material” and “insole material”. Three items were for visual experiment, namely “shoe body color”, “shoe body material” and “insole material”. Two items were for synesthesia experiment, namely “shoe body material” and “insole material”. Based on composing elements, 14 categories were further differentiated for tactile experiment, and 27 categories for visual experiment (Table 5).

Table 5. Items and categories for single sensory and synesthesia experiment
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3.4 Kansei Evaluation Experiment

The results show that (1) there is significant differences on the Kansei image of the shoes with different materials. In the tactile experiment of “shoe material”, the mesh material has the Kansei image of relieved, convenient, professional and delicate, but not comfortable or noble; (2) tactile, visual, and visual & tactile Kansei image are different even on the same material. The visual & tactile is highly correlated with single tactile image. For example, the “flannel” material has the image of “comfortable” both in the “tactile” and “visual & tactile” experiments, but of “relieved” while in the “visual” experiment; (3) the insole and shoe body share the same image, both have significant differences; (4) the results of the quantification theory type I show that “relieved”, “convenient”, “comfortable”, “professional”, “noble” and “delicate” are relevant to the “color of the shoe body” and the most influential category is “black” color.

4 Conclusion

Different personality groups have different preference on the material and color of shoes. Taking “dominant personality” as example, sample 2 (embroidery cloth), sample 3 (flannel), sample 4 (leather), sample 5 (knitted fabric), and sample 6 (cloth) are preferred in tactile experiment, but not sample 1 (mesh) and sample 7 (cowhide surface). And in the visual experiment, all materials are preferred only sample 1 (mesh) is average level. While in the visual & tactile experiment, all of the materials are preferred. Therefore, the preference of functional shoes will gradually become stronger after being visually and tactilely contacted for this group of elderly.

According to the research results and analysis, we can understand the Kansei preferences of the elderly people for functional shoes, and help designers or related footwear manufacturers to design and produce products that meet the needs of the elderly, and build the guidelines for Kansei evaluation of functional footwear for the elderly accordingly.