Keywords

1 Introduction

Along with the industrial progress and the improvement of life quality, the product functionality and usability have become the basic demands. The modern users lay more emphasis on pleasure, special use experience and memory empathy brought by the products. social values gradually become open and diverse, people transit from material to spiritual enjoyments, pursuing fashion and beautifying oneself have become a significant aesthetic tendency in modern time. Under such circumstances, consumer emotions are stronger, consumer demand level and contents are various. Particularly, consumer demand level rises from low to high, consumers pay attention not only on qualities and functions, but also on art, culture, symbol, individual satisfaction and joyful spirit of products. Emotional shopping tendency of consumers determines that emotional elements will be emphasized by more and more designers in future. Design directed by emotional content can be regarded as the heart of current design practices, research, and education (Demirbilek and Sener 2003). In another word, emotions are “felt” and can play significant roles during product interactions, such as impacting the decision of whether or not to buy (Jordan 2000; Norman 2004). Khalid (2001) pointed out, “the decision to buy can be momentary, so consumer demands can then be created very quickly, while other demands are long established.” Relying on individual judgment and preference, consumers buy products which can fulfill their subjective consciousness. Products which not only have cool appearances, satisfying functions and high qualities, but also can bring consumers psychological satisfaction are demanded in market. What consumers actually want are high-quality products which symbolize individual character, taste, identity and position. Under such situation, exploring consumer demands, expectations and preferences is necessary and significant. However, it can be challenging to measure consumer preferences and emotions on products and risky to develop new products. It has been estimated that up to one third of new products fail at the launch stage (Cooper and Kleinschmidt 1987). So it can be told that it is crucial to capture their emotional feedback on the products, because consumers tend to make buying decisions increasingly emotionally, avoiding the rational processing of large quantities of information (Katicic et al. 2006). Thus, more and more companies are willing to invest on researching the relationship between consumer emotions, references and new products; in order to design more attractive products and satisfy consumer expectations, consumer preferences and emotions on new products shall be learned. Moreover, it is important that product designers are sufficient for designing attractive new products, because attractiveness of new products themselves plays a key element impacting consumers’ purchasing decisions (Masato 2000). However, it is absolutely not easy to scale consumer references and emotions on products.

2 Related Work

Kansei Engineering and relevant researches have been largely promoted and consumers’ subjective emotional demands are valued in product design. As a customer-emotion-oriented new product developing technology, Kansei Engineering is defined as “a technology which materializes consumer emotions and images on products into design elements” (Nagamachi 1995), it is successfully applied in actual product design and has already been widely used in product design to explore the relationship between consumer emotions and product design elements. Owing to the fact that human emotions are extremely subjective, circumstance-related and individual, an accurate measurement of consumer emotions is generally impractical. In this regard, to consolidate consumer’s emotional requirements, Kansei engineering advocators suggested a new perspective on human emotions, i.e. the use of Kansei words or adjectives to represent various emotions (Ota and Aoyama 2001). Relation between product design elements and product kansei images are explored in Kansei Engineering. The general idea is: firstly, define consumer emotional demand space and product design space; secondly, select proper adjectives for products among numerous adjectives and match them with test samples; thirdly, inquire consumer emotions through Semantic Differential Method and establish the relationship between consumer demand space and product design elements. But after all, only consumer emotions rather than preferences on products can be found with such evaluating method, so the products designed in such process may only have limited power to impact consumer satisfaction.

Researching consumer satisfaction plays an important role in early stage of product development, consumer subjective feelings about product are key affecting elements to consumer satisfaction, therefore, it is significant to find out affecting elements to consumer satisfaction and categorize consumer demands. Kano et al. (1984a, b) made a two-dimensional diagram to present the relationship between consumer satisfaction and fulfilling demand degree as shown in Fig. 1. On basis of consumer reactions, indexes are categorized with Kano Model as: must-be quality, one-dimensional quality and attractive quality. According to this theory, products with attractive qualities can make consumers satisfied while products without attractive quality can not (Kano et al. 1984a, b). Generally, attractive qualities are not expected and not expressed by consumers. They can bring “surprise” to consumers sometimes. If one-dimensional qualities are realized, consumer will feel satisfied, otherwise, customers will not (Lee and Newcomb 1997). Investigating consumer demands with Kano Model is an important part in new product development and innovation process. consumer comments are meaningful for new product development because consumer demands evaluation affects the success of new product development for target consumers. Rashid et al. (2010), Hwang et al. (2014) used Kano Model and Kano Regression Method, verified consumer preferences, satisfaction and emotional experiences inspired by social and cultural products. The results of their researches offered designers with a better cognitive approach about how to design better products to meet consumer demands.

Fig. 1.
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An illustration of the Kano model

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Same like material demands, emotional demands on style design are also human demands in essence, it is not difficult to understand that Kano Model can be applied in emotional area of style design. Yao Xiang et al. based on Kano Model Categorization Method and categorized emotional demands of style design as must-be quality, one-dimensional quality and attractive quality. Design emotion is represented and expressed with adjectives. Design emotional qualities correlate closely with design characteristics, about product style design, through investigating the relationship between style design characteristics and emotional demands, it can be judged that which design characteristic leads to what emotion and which emotion belong to which quality level. Yao and Hu (2014) evaluated beauty elements of vehicle appearance in their researches, during evaluation process, participants were asked to evaluate 12 beauty elements of vehicle appearance in Kano Bidirectional Questionnaire. According to evaluation results, it was found that consumer demands could be captured more accurately with Fuzzy Kano Model (FKM), and that importing FKM in dealing with consumer emotions was more objective and fairer than importing Kano Model. Their researches were beneficial for designers in recognizing these beauty elements of vehicle appearance and putting their efforts in improving attractive qualities and increasing consumer satisfaction, influential for customers in accepting vehicle appearance.

Markus Hartono and Tan Kay Chuan (2011) described how Kano Model was helpful to Kansei Engineering in services, they also introduced a comprehensive framework consisted of Kano Model and Kansei Engineering. Kano Model was applied and inserted in Kansei Engineering to reveal the relationship between service qualities and consumer reactions. In case studying, Kansei Engineering is applied to capture and transfer consumer emotional demands, Kano Model is used to assist Kansei Engineering and deeply explore the relationship between service elements and consumer emotions. Kansei Engineering promotes emotion elements to merge with product design elements, but it can not tell influences of different emotion elements on purchasing decisions. Tama et al. (2015) combined Kansei Engineering and Kano Model in their study to improve design of ceramic souvenirs and better meet consumer expectations. During study, they categorized or sorted emotion adjectives in accordance with Kano Model, then they calculated and analyzed the emotion adjectives which affected consumer satisfaction the most and developed such adjectives as key for further design.

Miryoku engineering was a research developed by Masao Inui and Japanese scholar Junichiro Sanui in referring to the book The Psychology of Personal Constructs written by clinical psychologist Kelly, which provides the designers a method to make the customers’ fuzzy perceptual cognition become specific when executing product development. It was understood that some ways to choose products by customers and the experience of successful product design can catch the products’ charm essence, thus a design full of charm would be created. The method clearly discussed the similarity or difference relationship in the comparison between object A and B mainly by individual interviews, thus the individual qualities of target objects were sorted out. The charm factors will be the key points to successful products if they can be obtained in the products design and development as well as applied and transformed to actual product aspects, so the extraction of charm has been worked on finding by many designers in the design process. The product evaluation construction method provides an analytic approach to product charm factors with theory basis among the related researches in miryoku engineering, providing stimulation according to the category of the theme and in the form of depth interviews to know the customers’ feeling about the products’ charm, making the participants have obvious feeling difference after the comparison of preference degree among participants, so the participants’ original concept to the subject will be known, thus leading to the participants’ more definite analyzing the original evaluation concept and connecting its upper abstract concept with lower specific description, and then a network diagram of participants’ evaluation structure of products will be sorted out.

3 Research Method and Process

“Miryoku” is a Japanese word, means “strong attraction”. So-called miryoku is a kind of power which appeals public feeling and make people puzzling, i.e. power which causes people confused, it can induce people to take certain actions, for example, consumer decision-making behavior. It is the subjective preference of consumers and has direct and close relationship with consumers’ values. From a design perspective, the extraction of miryoku is the element which a lot of designers are committed to look for in design process. Miryoku, can be regarded as a generic term of power to conquer public feeling such as allure, attraction, induced force, appeal and inspiring power, etc. Miryoku engineering is a research which helps designers better understand customers’ specific perceptual cognition and then catch a relatively accurate preference of customers. Miryoku engineering advocators suggested a new perspective on human emotions, i.e. the use of adjectives to represent various emotions. In this study, “kansei images” of E-scooter’s Front Face were led into Fuzzy Kano Model and entitled with particular “quality attributes” to explore the relationship between kansei images and customer satisfaction. In this study, using the Evaluation Grid Chart of Miryoku Engineering, the author interviewed participants who were over 30 years old and had studied industrial design for more than five years, to catch the personal cognition of attractiveness of E-scooter’s Front Face.

Now people is paying more and more attention to living environment quality and physical health. Green travel is one of social hot topics. E-scooter is naturally the first choice, especially a equipment suitable for mid-short distance traffic, according to the survey, the main reason which citizens select light electric vehicle as transportation means instead of walk is: car is expensive, bicycle requires human power to drive, bus system is not perfect enough, the driving of motorcycle is relatively dangerous and meanwhile prohibited in many cities, however, E-scooter avoids training, cumbersome registration procedure and expensive insurance cost. As a personal traffic carrier, with the characteristics of low carbon and environmental protection, electric vehicles will become one of mainstream traffic tools in the future. researchers and designers engaged in this field need to study user’s preferences based on miryoku engineering.

In order to analyze the attractive factors of E-scooter’s front face, an interview is conducted by using EMG method. Interview time is 1 h and interview place is in a separate room which has no external interruption. The number of people who participated in investigation and survey is 30. They are made up of 18–38 years’ old men and women, some of them have 2 years’ experience of driving E–scooter, some are designers who study E-scooter. These experts and scholars as well as experienced E-scooter drivers will be asked the attractive factors they think with regard to E-scooter’s front face, thus explore the key factors E-scooter’s front face design generates attraction. Specific method is as follows: 1. Prepare 20 sample drawing cards, card size is half of A4 paper size and every sample card size has the same specification, each sample card is selected from a variety of E-scooter’s front face, among which are made by several major manufacturers in market, interview will be conducted based on the classification of 20 sample cards. 2. The cards which are partial to E-scooter’s front face are grouped by their preferences. 3. The original evaluation item, which is established by different preferences and reasons, original evaluation item will be asked by comparing groups. 4. Each original evaluation item is processed into “upper” and “lower” levels. The upper level is asked the reason of original evaluation item and the lower level is asked the specific features of evaluation item. According to above said process, the structure of evaluation item of each participant can be displayed. Table 1 shows the preference of a participant to E-scooter’s Front Face.

Table 1. Preference of a participant to E - scooter’s Front Face
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In order to make the attractive factors more representative, the author used the KJ Method to simplify the items. These evaluation items were selected to form the questionnaire in the next step. KJ Method to simplify the headlight of E-scooter’s front face is shown in Table 2.

Table 2. KJ Method to simplify the headlight of E-scooter ’s Front Face
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Attractive factors of E-scooter’s front face were led into “Fuzzy Kano Model” and entitled with particular “quality attributes” to explore the relationship between attractive factors and customer satisfaction. In traditional Kano model survey, participants give only one answer to positive and negative questions, this ignores the uncertainty of participant’s thought. When the answer which a customer gives to a product attribute is uncertain, the survey data to this part of the customer by traditional Kano model is not accurate. Considering the uncertainty of customer satisfaction, a demand classification method of fuzzy Kano model is put forward.

Both fuzzy Kano model and traditional Kano model conduct survey of customer satisfaction in the form of positive and negative questionnaire, the biggest difference lies in the design of the questionnaire. Traditional Kano questionnaire only allows you to select a most satisfied answer for positive and negative questions, however, fuzzy Kano questionnaire allows clients to give fuzzy satisfaction values to multiple survey items (in the form of percentage, their values are between [0, 1], the sum of row elements is equal to 1). The questionnaires of traditional Kano model and fuzzy Kano model are shown in Tables 3 and 4 respectively.

Table 3. Traditional Kano questionnaire
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Table 4. Fuzzy Kano questionnaire
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4 Discussion and Analysis of Results

First of all, take the above simplified 10 upper level attractive factors as evaluation items, and ask participants’ ideas respectively with a group of bidirectional questionnaires (sufficient and unsufficient quality). The influence of every perceptual image vocabulary on satisfaction degree of customers can be known by calculation, thus, we deduce which words belong to attractive quality from the 10 perceptual image words. Table 5 shows the result analysis of FKM analysis.

Table 5. Attribute priorities of upper level attractive factor
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Take the fuzzy Kano questionnaire of a participant as example, assume that the function matrix X = [0.7 0.3 0 0 0] can realize, the function matrix Y = [0 0 0.5 0.5 0] cannot realize, they generate fuzzy interactive matrix. The generated fuzzy interactive matrix is made positional correspondence of Kano quality attributes decision matrix, the membership degree vector of A, M, O, I can be known, ta = 0.7, tm = 0, to = 0, ti = 0.3. Because the same evaluation factor generally belongs to multiple Kano attribute category at the same time, in order to obtain more accurate and reliable data, threshold α is introduced for filtering. For the choice of α values, it is found by Meng and He (2013), (through setting different values of α), that α = 0.4 is the optimal value, it can guarantee information not only distortionless, but also less cross. If the membership degree vector t of Kano attribute category is greater than α, it is set that the attribute vector of this attribute category is expressed by 1, otherwise expressed by 0. Above steps are repeated, tendency categories of demand for products of each participant are statistically analyzed, the highest frequency tendency of demand for the product of participants is the attribute category of demand.

According to FKM classification results, there are 10 charm quality attributes, among which minimalistic, delicate and lovely are three types of charismatic quality, other 7 types are indifferent quality, then designers can firstly integrate charismatic quality attributes with the design of E-scooter’s Front Face.

For example, emotional vocabulary minimalistic, at present, in the fierce competition and fast pace modern city life, the mental and psychological pressure of people increase gradually, they hope they can relax their tense nerve, make body and mind get stretch. The concise and straightforward style can provide real psychological support. Specifically, minimalistic style is characterized by rejecting delicate and intricate decoration form, seeking a combination of simple geometric shape and fluent lively line/plane. When consumers find E-scooter’s Front Face has minimalistic characteristic, they psychologically feel fresh and clear, thus are attracted by the appearance of E-scooter’s front face. That is to say, it takes a key role in the design form of E-scooter’s front face to strengthen the research of minimalistic style. The author thinks that its style design can be summarized into abstract geometrical body, and carry on combination permutation arrangement by making full use of three forming rules-dot, line, face, can increase modelling change in local place, thus design minimalistic modelling so as to make E-scooter’s front face attractive.

From the point of delicate view, delicate refers to product modelling is relatively fine, the design of main structure style is more reasonable, the treatment of a length of circular arc, a raised modeling as well as local modelling scale, quantity relationship in product shape is more harmonious, lead to the exquisite overall visual effect of products. With the development of social economy, people begin to pursue the high level of life quality, reflected in pursuit of quality and class when purchase E-scooter. In the choice of E-scooter, when consumers find E-scooter’s front face with fine quality, will psychologically feel delicate and elegant, can produce a kind of slap-up feeling, thus are attracted by E-scooter’s front face.

Once more, from the point of lovely view, lovely is a psychological natural reaction to some characteristics of product modeling, such as cartoon, novel and fun. Lovely products are usually designed by using bionic technique, realistically reproduce the form of natural things, let people have a unique taste after observation, as a result, the psychological distance between people and products becomes short. As the life rhythm of modern people speeds up, the life pressure of people increases, people expect to pursue the happy relaxed way of life, therefore, tend to pursuit a product with fun and friendly feeling to entertain their life. Based on this, when consumers find E-scooter’s front face has lovely feature, will psychologically feel affinity, be associated with a kind of fun and joy, and have a unique taste experience, thus be attracted by E-scooter’s front face.