Mobile Banking Service Design Attributes for the Sustainability of Internet-Only Banks: A Case Study of KakaoBank

Abstract

The rapid development of information technology and the diffusion of Internet-only banks have made mobile banking an essential service in Korea. Meanwhile, the spread of non-face-to-face services triggered by the COVID-19 pandemic is encouraging continuous innovation in the banking sector. This study explored the application design attributes of mobile banking in the context of the sustainability of Internet-only banks. Specifically, this study empirically analyzed user usage intention and attitude using the theory of planned behavior (TPB) and seven service design attributes derived from previous studies, namely: information quality, service quality, utilitarian value, hedonic value, ease of use, usefulness, and aesthetics. Information quality, utilitarian value, ease of use, and usefulness positively affected sustainable usage intention and attitude, while service quality, hedonic value, and aesthetics did not affect sustainable usage intention and attitude. Notably, this study derived the theoretical attributes of financial service design from the user’s perspective, which has not yet received much attention in existing research, by applying the TPB. It also identified mobile banking service attributes that may support the sustainability of financial services, which lays a foundation for further research. Moreover, this study’s findings offer insights into which user touchpoints designers should focus on when developing services.

1. Introduction

The first Internet-only banks in Korea were KakaoBank and Kbank, launched in 2017, and Toss Bank, launched in 2021. Recently, the number of mobile-banking-service users has been growing explosively. Customer deposits in Internet-only banks are also increasing geometrically every year. Accordingly, the market is gradually expanding its influence. Notably, the expansion of big tech companies such as Kakao and Naver into the financial business is driving change in global financial services. Amidst the Fourth Industrial Revolution, such companies are rapidly growing by creating new financial businesses and contributing to the formation of new cultures. Moreover, the growing demand for the revitalization of the non-face-to-face economy triggered by the COVID-19 pandemic has led to the rapid development of mobile banking services [1].

Internet-only banks are in a situation where the “sustainability” of mobile banking, which is their major service, is constantly being threatened due to the expansion of existing commercial banks into the mobile banking business as well as the emergence of similar financial services. Commercial banks’ entry into mobile banking is standardizing services, which means that commercial banks now offer services similar to Internet-only banks, such as KakaoBank and Kbank. Customers do not use Internet-only banks as much as commercial banks because regulations prevent them from providing face-to-face services (e.g., loan provision). In particular, most people in the consumer finance market tend to stay with the same bank; as a result, Internet-only banks are now facing great challenges in terms of market expansion and sustainability [2].

As market power shifts from being firm-centered to consumer-centered, customer behavior, customer–firm interactions, and the customer context have become important value criteria; within these conditions, the demand for service advancement is also increasing in the on-demand market, in which the paradigm is becoming more customer-centered [3]. In particular, for mobile application service design with direct user touchpoints, it is difficult to guarantee success without an in-depth understanding of the users. Furthermore, the financial sector, which includes commercial banks and securities firms, is developing services suitable for the mobile environment and attempting to secure users by providing various advanced technologies [4]. In this context, an adequate service design quality is necessary for mobile banking to survive after securing a number of users. Therefore, mobile application design is becoming more and more important in the financial sector. However, there is insufficient research on how to differentiate usability and service (UI, UX) design and how Internet-only banks should differentiate their mobile banking services from those created by commercial banks.

The digital transformation (DT) triggered by the COVID-19 pandemic has highlighted several interests central to the economic foundations of Internet-only banks, such as reducing the waste of depletable resources (e.g., papers and pens), addressing the climate crisis, designing low-carbon strategies, and creating new businesses and comprehensive behavior that support social sustainability [1]. Therefore, this study sought to uncover service design attributes that support the sustainability of mobile banking services from Internet-only banks and empirically analyzed their impact on user intention to use these services based on academic and theoretical research. To identify the design attributes of mobile banking services created by Internet-only banks, we conducted a case study of a mobile banking application by KakaoBank, which currently has the biggest number of users among all mobile banking service providers in Korea.

This study empirically verified the design attributes of KakaoBank’s mobile banking by targeting users with experience using the service and applying a theoretical framework based on the theory of planned behavior (TPB). The results will offer insights useful for Internet-only banks seeking to establish customized service policies for users and operate sustainable services. In sum, this study sought to answer the following questions:

• What UX design antecedents affect the use of mobile banking services by users?
• What factors differentiate the mobile banking services of Internet-only banks from the Internet banking and telebanking services provided by existing banks?
• What mobile banking service design attributes affect user usage intention?

This paper comprises six sections, which present the study as follows: Section 1 introduces the study by describing the research background, purpose, and scope. Section 2 systematically summarizes Internet-only banks, mobile banking services, the TPB, and the conceptual framework based on a literature review and existing data. Section 3 develops the research model and sets up the related hypotheses. Section 4 explains the measurement items of the research variables and the research methods, such as data collection, to validate the research model. Section 5 reviews the results of the analysis. Section 6 summarizes the study results and provides the implications and limitations of the results.

2. Theoretical Framework

2.1. Internet-Only Banks and Mobile Banking Services

Internet-only banks refer to “banks without physical branches”, which deliver financial services online that were historically provided offline [5]. They are also referred to as “virtual banks”, since they offer financial services virtually instead of physically [6]. Internet-only banks allow customers to deposit and withdraw money from most automated teller machines (ATMs) in various locations in Korea. Notably, they have been working to differentiate themselves from existing banks by focusing on securing customers by offering various aggressive services, such as commission-free withdrawals and transfers and non-face-to-face loans. KakaoBank mini, launched in 2021, is an electronic prepayment service targeted at teenagers that can be used with just mobile-phone verification and without opening or linking a bank account. KakaoBank mini also supports simple transfers between friends on KakaoTalk. With 26-week installment savings, customers can create a Kakao Friends character or share their successful experience with friends or family. Kakao has also increased banking accessibility for teenagers by providing online and offline payment methods using mini cards with cute characters [7]. The features on its platforms enable customers to easily transfer money via SMS or messengers such as KakaoTalk (e.g., they can send cash for weddings or funerals) and allow multiple customers to view the details of an account at once so that they can split payments. As such, mobile banking has brought considerable social, economic, and cultural changes. In 2022, efforts were made to make the system more sustainable through offering more open banking services; for example, a single application could be used to access accounts with or to apply for personalized loans from different financial companies [8].

As shown in

Table 1. Comparison of Internet banks in Korea [9].

	Tossbank	Kakaobank	Kbank
Number of customers (in thousands)	4400	19,380	7380
CSS model	TSS (Toss Scoring System)	Kakaobank Scoring	Development of CCS Model Using Telecommunication Company Data
Medium interest rate loan ratio	40%	24%	24%
Target of mid-interest loans by the end of 2022	42%	25%	25%

, as of 2022, Toss Bank had 4.4 million users, KakaoBank had 19.38 million users, and Kbank had 7.38 million users. KakaoBank is currently the top banking application in Korea. In addition, Internet-only banks have recently expanded their financial services for thin filers with insufficient financial history by upgrading the credit scoring system (CSS), once again demonstrating the potential of Internet-only banks for discovering and actively embracing sound customers with bad credit who have not been rated properly despite having a real income and repayment capacity, such as people beginning their careers, small business owners, and employees of small- and medium-sized enterprises (SMEs) [9]. The detailed activities of each bank are as follows: Kbank, Korea’s first Internet-only bank, is a bank in the banking sector. Recently, it increased its capital by 400 billion KRW and began to actively expand into the market by launching new products, such as apartment mortgage loans and Hot Deal installment savings. In 2021, KakaoBank received public attention for its initial public offering (IPO). At the time of its initial listing in August 2021, KakaoBank’s total market value was approximately 40 trillion KRW—this figure is equivalent to the sum of all four major financial holding companies in Korea, and it continues to grow. Additionally, KakaoBank’s net interest margin (NIM) is higher than that of major commercial banks and is also on the rise, which also indicates the firm’s likelihood of being profitable [10]. Toss Bank is also growing rapidly, even though it was a latecomer launched in 2021. Recently, they have gathered data on existing banks and credit card companies and combined non-financial alternative data (e.g., credit-card-use details and patterns), account transaction details and patterns, and insurance payment details to actively improve their services.

As of late June 2022, there were 162.55 million customers registered for mobile banking in Korea, evidencing a 6.0% year-over-year increase in customers and a 9.2% increase in average daily use [11]. As shown in Figure 1, the number of users, the number of uses, and the amount of use for mobile banking in Korea have been showing stable growth every six months since 2020. In addition, the rates of increase and decrease in the number of users is maintained at an average of 6%. The rate and volume of mobile bank use are rapidly increasing compared to Internet bank use. One thing to note is that the amount of loan applications rapidly increased in 2022 due to the launch of new loan products by Internet-only banks, such as KakaoBank, Kbank, and Toss Bank. This can be a meaningful indicator for predicting the future growth potential or direction of Internet-only banks that offer mobile banking as their main service.

“Mobile banking services” are financial services that provide users with the ability to transfer funds between accounts, confirm transaction details, and perform direct payments using microbrowsers on their mobile phones through WAP, Java, and GPRS [13]. These services allow customers to bank on the move and without space constraints, which allows them to save the time and effort they would have spent if they were using existing PC-based Internet banking. Moreover, the services offered by Internet-only banks, such as KakaoBank, are making multidimensional efforts to facilitate sustainability in addition to securing customers by developing intimacies based on the giant platform called KakaoTalk, which is differentiated from the services provided by existing commercial banks. To this end, they are attracting users more rapidly than other services by reinforcing UX design elements, such as ease of use, playfulness, and aesthetic appeal [14]. Smartphone-based mobile banking services have great advantages, such as eliminating network dependence on mobile carriers from the bank’s perspective, directly distributing services to users through an open app store or website, and providing unique and differentiated services. Moreover, since application programs can be developed and distributed for each smartphone OS rather than individual devices, the costs and efforts required for development and maintenance can be saved. Meanwhile, users can download and install programs more quickly and easily through various channels, such as their mobile carrier’s app store, marketplace, or bank website. With most smartphone users using flat-rate data plans, the diffusion of mobile banking service customers is expected to continue to increase [4].

2.2. Theory of Planned Behavior

The TPB [15] and the theory of rational action (TRA) [16] are actively used in marketing to discover the psychological mechanism that induces the actual purchase behavior of consumers. In particular, the TPB is widely used in the context of consumer behavior to explain the psychological mechanism that determines the intention behind a specific behavior, including the attitude toward the behavior, subjective norm, and behavioral control [15]. Since the intention to use a virtual space, such as an online or mobile service, is based on a comprehensive evaluation of the service, it can be used as an important indicator when evaluating the preference for the service [17]. Applying the TPB to mobile banking service design reveals that the psychological attitude of users toward the service formed by the service design is most closely related to forming the intention that leads to behavior. Therefore, this study extracted various factors that can affect user attitudes.

2.3. Conceptual Framework

The user’s attitude toward a service shapes their intention to use the service. The TBP can explain the process in which an intention may lead to a behavior; accordingly, it is an important theoretical framework for this study. In particular, in forming attitudes toward a service, service design attributes can be directly related to user touchpoints, which is why various service design attributes are necessary. Of course, user attitudes may be formed from more diverse factors; however, this study’s scope was limited to service design and phenomena that mostly occur on mobile service platforms (see Figure 2).

3. Research Model and Hypotheses

This section presents a research model based on the TPB [15] in which mobile banking service design attributes impact user attitudes toward the service and usage intention and explains the correlations between the according variables.

3.1. Research Purpose and Model

The purpose of this study was to empirically investigate the service design attributes that can be continuously used by mobile banking users from the user perspective. Therefore, this study’s findings have implications for the theory and practice concerned with which elements mobile banking service design should emphasize. To perform this study, we built the following research model (see Figure 3):

3.2. Research Hypotheses

3.2.1. Perceived Information Quality

Online service users objectively chose to perform particular purchasing and use behaviors and prefer newly customized information [18]. The “information quality” of an online application refers to the user’s evaluation of the accuracy of the content, format, and timeliness of the service [19,20]. Users engage information to identify and distinguish product or service quality [21,22]. It is important for the information to be accurate, fit for the purpose at hand, and easy to understand [18]. Information users will have a positive attitude toward information quality only if the information offered by the service is updated and different from the information they can access from their competitors [23].

Therefore, based on previous studies, we defined “perceived information quality” as the consumer’s perception and evaluation of the information provided by a mobile banking service. Accordingly, we set up the following hypothesis:

Hypothesis 1. 

Perceived information quality positively affects attitude toward the use of a mobile banking application.

3.2.2. Perceived Service Quality

Studies on service quality in consumer behavior mostly use the concept of perceived service quality. Here, “perceived quality” is defined as a user’s evaluation of the overall excellence or superiority of a product or service [24,25]. “Product quality” is defined as the objective quality related to the physical attributes or functions of the product itself and the subjective quality related to individual perception [26]. Therefore, if service providers help customers understand the benefits that can be obtained from the service before they feel it or think about it, they may be able to change the customers’ attitudes [27]. Based on previous studies, we defined “mobile banking service quality” as the consumer’s judgement of the overall excellence, superiority, or differentiation of the service. Accordingly, we set up the following hypothesis:

Hypothesis 2. 

Perceived service quality positively affects attitude toward the use of a mobile banking application.

3.2.3. Perceived Utilitarian Value

The user’s perception of a service’s utilitarian value reflects whether the user believes they can effectively obtain the kind of information they want from the service, and it is measured in terms of task-oriented, cognitive, and non-emotional outcomes [23]. When measuring the utilitarian value of a mobile banking application, the focus is primarily on its task-specific outcomes. Utilitarian value most strongly affects cognitive attitudes, such as economic judgments related to money, efficiency, and convenience [25]. In this study, we situate perceived utilitarian value as a leading indicator of economic judgment and treat it as the customer’s belief as to whether they can conveniently perform their desired tasks using a mobile banking service in a way that they think saves them time or money. Therefore, based on previous studies, this study defined perceived utilitarian value as the degree to which the user believes they can use a mobile banking service to attain their goals and thus enjoy cognitive rewards. Accordingly, we set up the following hypothesis:

Hypothesis 3. 

Perceived utilitarian value positively affects attitude toward the use of a mobile banking application.

3.2.4. Perceived Hedonic Value

“Hedonic value” reflects the various senses, imaginations, and emotional aspects of the consumer experience [28]. It is an intrinsic motivation that encourages consumers to act according to the hedonic function of the service, rather than a utilitarian motivation that encourages customers to make decisions related to purchasing, service use, or task performance [23,29]. Consumers can accept hedonic value through benefits, such as discounts/coupons, or events within the service. Consumers with a hedonic motivation tend to use services to gain expertise in their interests and experiences with a new trend, even though they do not pay for things within the service [30]. As mentioned in the introduction, mobile banks market themselves using various events and timely services. Thus, based on previous studies, we defined “hedonic value” as the degree of pleasure and sensory and emotional rewards that can be obtained by using a mobile banking service. Accordingly, we set up the following hypothesis:

Hypothesis 4. 

Perceived hedonic value positively affects attitude toward the use of a mobile banking application.

3.2.5. Perceived Ease of Use

“Ease of use” is defined as the degree to which users can use a particular Internet technology (IT) without much effort or difficulty. It mostly aligns with the technology acceptance model (TAM). The main items are easy to learn, understand, use, and control, and its functions are flexible [31]. Accordingly, ease of use represents the degree to which users feel a particular system will not waste their time or effort; a good ease of use increases the customer’s intention to use the system and may therefore lead to actual usage behavior [32]. Specifically, ease of use generally affects intention through the usefulness of the IT or system acceptance process, but it can also directly affect behavioral intention [31,33,34]. Moreover, a previous study proved that perceived ease of use can directly affect the intention to use mobile commerce services, which speaks to its impact on intention to use mobile banking services [35]. Therefore, we defined “perceived ease of use” as the expectation that the user will not have to expend much effort to use the mobile banking technology or system. Accordingly, we set up the following hypothesis:

Hypothesis 5. 

Perceived ease of use positively affects attitude toward the use of a mobile banking application.

3.2.6. Perceived Usefulness

Usefulness is a key variable of the TAM, along with ease of use. Specifically, “usefulness” indicates the subjective expectation that using a particular IT can enhance the user’s task efficiency [36], and it is widely used as a variable that directly affects dependent variables, such as attitude or acceptance intention [31,33,37]. Perceived usefulness has been proven to directly affect user attitude and intention in e-commerce. A study on consumers engaging in online shopping showed that perceived usefulness affects user attitude toward shopping [38] as well as purchase intention in physical environments (e.g., shopping malls) [39]. Therefore, we defined “perceived usefulness” as the subjective expectation that using mobile banking can increase task efficiency. Accordingly, we set up the following hypothesis:

Hypothesis 6. 

Perceived usefulness quality positively affects attitude toward the use of a mobile banking application.

3.2.7. Perceived Aesthetics

Outward appearances can influence perception. For example, the visual beauty of natural objects, buildings, or products frequently used in daily life can affect human interactions [40,41,42]. Design aesthetics based on visual beauty also affect user emotions, which can help form a powerful brand awareness of products or services [43]. For products such as smartphones, design aesthetics impact product preferences [44]. Studies on user experience, environment, and design have also revealed that aesthetics critically impact system evaluations based on user interactions and positively affect various interactions, such as usability and emotional satisfaction [45,46]. Therefore, we defined “perceived aesthetics” as the outward beauty of the mobile banking application or the pleasure derived from it. Accordingly, we set up the following hypothesis:

Hypothesis 7. 

Perceived aesthetics positively affects attitude toward the use of a mobile banking application.

3.2.8. Attitude toward the Use of a Mobile Banking Service

In the TPB, “attitude” refers to the psychological tendency expressed by the preference for or dislike of a particular object [47]. Many previous studies have proven that customer attitude toward shopping positively correlates with purchase intention [48]. We defined “attitude toward online shopping” as the consumer’s perception of the characteristics of an online store and the degree to which the store’s subjective importance increases when the consumer favorably evaluates its characteristics [49]. Accordingly, we set up the following hypothesis:

Hypothesis 8. 

Attitude toward using the mobile banking service positively affects usage intention.

While many variables shape user attitude, this study was based on previous studies that focused on which indicator form attitudes in the TPB. Therefore, we used seven independent variables based on the standard mobile banking application service design attributes listed above, namely: perceived information quality, perceived service quality, perceived utilitarian value, perceived hedonic value, perceived ease of use, perceived usefulness, and perceived aesthetics. The dependent variables were attitude toward the service and usage intention.

Ultimately, we established the eight hypotheses listed above (H1–H8), seven of which focus on mobile banking application service design attributes and one of which focuses on the correlation between attitude and usage intention. All hypotheses had a positive effect, as shown below (see

Table 2. Hypothesis of the study.

No.	Hypothesis
H1	Perceived information quality → Attitude toward use	Perceived information quality positively affects attitude toward the use of a mobile banking application.
H2	Perceived service quality → Attitude toward use	Perceived service quality positively affects attitude toward the use of a mobile banking application.
H3	Utilitarian value → Attitude toward use	Perceived utilitarian value positively affects attitude toward the use of a mobile banking application.
H4	Hedonic value → Attitude toward use	Perceived hedonic value positively affects attitude toward the use of a mobile banking application.
H5	Perceived ease of use → Attitude toward use	Perceived ease of use positively affects attitude toward the use of a mobile banking application.
H6	Perceived usefulness → Attitude toward use	Perceived usefulness positively affects attitude toward the use of a mobile banking application.
H7	Perceived aesthetics → Attitude toward use	Perceived aesthetics positively affects attitude toward the use of a mobile banking application.
H8	Attitude toward use → Use intention	Attitude toward using the mobile banking service positively affects usage intention.

):

4. Research Method

4.1. Sample and Data Collection

We collected data using a questionnaire to test our hypotheses. The items used in the questionnaire were validated by previous studies, and all items except the general characteristics of the respondents were rated on a 7-point Likert scale.

The survey items were developed according to the research purpose with reference to previous studies and existing tools. A pretest was conducted with experts with experience using mobile banking to test the validity and reliability of the items. Items that were difficult for respondents to clearly understand or that were somewhat awkward were corrected to be more suitable for mobile banking with reference to the original text.

To collect research data, survey respondents were selected from users with experience using mobile banking services, and the survey was conducted both offline and online using Google Docs. The survey was conducted for 6 days from 3 to 8 January 2021. A total of 230 copies of the questionnaire were retrieved. After excluding 30 copies with insincere responses that were impossible to use, a total of 200 copies of the questionnaire were used for the statistical data analysis. In addition to limiting the age of participants to those in their 20s or older who have used mobile banking during the survey, gender, region of residence, occupation, and responses to mobile banking services used were randomly collected.

4.2. Measurement of Research Variables

The operational definitions of the variables and measurement items used to test the hypotheses are as follows (see

Table 3. Operational definitions and measurement items of the constructs.

Constructs	Operational Definitions and Measurement Items	References
Perceived information quality (IQ)	Consumer evaluation of information provided by mobile banking (1) This mobile banking platform provides accurate information necessary for using its services. (2) This mobile banking platform provides sufficient information necessary for using its services. (3) The information provided by this mobile banking platform is useful to me. (4) The information obtained from this mobile banking platform is valuable to me.	Kuan et al. [50]
Perceived service quality (SQ)	Consumer judgment of the overall superiority or excellence of service (1) The services provided by this mobile bank are reliable. (2) The services provided by this mobile bank are trustworthy. (3) The services provided by this mobile bank are worth using continuously.	Oh [51]
Utilitarian value (UV)	Belief in cognitive rewards for goals that can be obtained by using the mobile banking service (1) I always complete what I intend to (e.g., account transfer and remittance) while using mobile banking. (2) I can immediately use the function I want to use on this mobile banking platform. (3) This mobile banking platform has the functions I need. (4) This mobile banking platform is convenient to use.	Babin et al. [23]
Hedonic value (EV)	Belief in pleasure as well as sensory and emotional rewards that can be obtained by using the mobile banking service (1) Compared to other things I can do at this time, I truly enjoy spending time using the mobile banking platform. (2) I feel excited and my heart flutters when using the mobile banking platform. (3) I feel curious about using the mobile banking platform when I use it. (4) I feel that using mobile banking is beneficial.	Babin et al. [23]
Perceived ease of use (UE)	Expectation that using the mobile banking technology or system will not require much effort from the user (1) I can easily make a deposit, transfer money to other accounts, or make a wire transfer on the mobile banking platform. (2) I can easily use the mobile banking platform. (3) I can easily access the service I want on the mobile banking platform. (4) It will be easy to learn how to make a new account or complete a wire transfer on the mobile banking platform.	Sayaf, A.M. [36]
Perceived usefulness (UF)	Subjective expectation that using the mobile banking service will increase task efficiency (1) I can obtain useful information from the mobile banking platform. (2) Mobile banking efficiently provides services, such as account transfers, remittance, and deposits. (3) Using mobile banking will be useful. (4) Mobile banking has more advantages than disadvantages.	Sayaf, A.M. [36]
Perceived aesthetics (ET)	Outward beauty of the mobile banking application or the pleasure associated with it (1) I think the design of the mobile banking platform is creative. (2) I think the design of the mobile banking platform is fascinating. (3) I think the design of the mobile banking platform makes me feel good. (4) I think the design of the mobile banking platform is pretty.	Tractinsky et al. [52]
Attitude toward use (AT)	Psychological tendency and preference determined by the customer’s evaluation of the mobile banking service (1) I am developing a close relationship with the mobile bank. (2) I feel relaxed when using this mobile banking service. (3) I have a positive attitude about spending time using the mobile banking platform. (4) I have a favorable opinion of this mobile bank.	Ashari, H. et al. [53]
Usage intention (IT)	Intention to purchase this product due to consumer attitude toward mobile banking (1) I think I will definitely use this mobile banking service in the future. (2) If I have to decide right now, I may use the mobile bank. (3) I intend to use this mobile bank in the future. (4) I would like to recommend this mobile bank to others.	Sadyk et al. [54]

):

5. Research Analysis and Results

We used the IBM SPSS 25 data analysis program to empirically analyze the hypotheses. Because we are in a relatively early stage of establishing a theory for measuring the correlation between user attitude and usage intention in mobile banking service design and because the causal relationship must still be predicted, we analyzed the data by using this program to conduct a factor analysis and multiple regression analysis after analyzing the demographic characteristics.

5.1. Demographic Characteristics

The results of classifying the respondents by their demographic characteristics are shown in

Table 4. Characteristics of sample data.

Category		Frequency	Percentage (%)	Category		Frequency	Percentage (%)
Gender	Male	98	49%	Occupation	Self-employed	4	2%
	Female	102	51%		Sales/service	6	3%
Age	20s	64	32%		Functional jobs	6	3%
	30s	44	22%		Clerical/technical jobs	70	35%
	40s	50	25%		Executive/management jobs	18	9%
	50s	42	21%		Freelance/specialized jobs	24	12%
Region	Seoul	60	30%		College students	28	14%
	Busan	14	7%		Graduate students	2	1%
	Daegu	12	6%		Homemakers	24	12%
	Incheon	8	4%		Unemployed	12	6%
	Daejeon	4	2%		Others	6	3%
	Gwangju	6	3%	Current service	KakaoBank	51	26%
	Ulsan	2	1%		Kookmin Bank	29	15%
	Gyeonggi	74	37%		Shinhan Bank	29	15%
	Chungbuk	4	2%		NongHyup Bank	25	13%
	Jeonbuk	4	2%		Woori Bank	20	10%
	Jeonnam	2	1%		Hana Bank	17	9%
	Gyeongbuk	2	1%		Kbank	16	8%
	Gyeongnam	4	2%		Industrial Bank of Korea	9	5%
	Jeju	4	2%		Other banks (enter the name of bank)	5	3%

. The ratio of men to women was 49:51, which indicates that the sample comprised nearly the same number of men and women. Meanwhile, the age distribution of the participants was also relatively even; however, there was a slightly higher number of respondents in their 20s. By region, Seoul and Gyeonggi were home to the highest numbers of participants. Regarding occupation, clerical/technical jobs were the most common. KakaoBank was the service used most by the respondents, followed by Kookmin Bank and Shinhan Bank.

5.2. Validation of the Measurement Model

This study examined the measurement model to analyze the reliability and validity of the measured values prior to validating the structure model for hypothesis testing.

We conducted an exploratory factor analysis using SPSS to analyze the construct validity of the research model. The standard for the correlation in a factor analysis based on the Marlowe–Crowne scale (1960) is at least 0.50, and our measurement items demonstrated both convergent and discriminant validity (see

Table 5. Results of the reliability and validity analyses of the research variables.

Measurement Variable	Number of Measurement Items	Mean	SD	AVE	Composite Reliability	Cronbach’s Alpha	VIF
IQ	4	5.676	0.844	0.712	0.886	0.844	2.458
SQ	3	4.566	0.924	0.854	0.932	0.911	1.320
UV	4	4.121	0.906	0.821	0.893	0.891	2.221
EV	4	5.100	0.901	0.811	0.944	0.886	2.512
UE	4	4.336	0.854	0.729	0.912	0.932	1.612
UF	4	4.276	0.903	0.816	0.902	0.954	2.145
ET	4	4.439	0.912	0.832	0.892	0.863	2.321
AT	4	5.116	0.872	0.761	0.912	0.911	2.201
IT	4	5.136	0.874	0.764	0.956	0.941	·

Note: The VIF value is for independent variables and not for usage intention (dependent variable); IQ = perceived information quality, SQ = perceived service quality, UV = utilitarian value, EV = hedonic value, UE = perceived ease of use, UF = perceived usefulness, ET = perceived aesthetics, AT = attitude toward use, and IT = use intention.

).

The reliability of the nine variables was confirmed; their Cronbach’s alphas were all over 0.5 or 0.6 in the initial analysis. Convergent validity was also confirmed; the average variance extracted (AVE) was over 0.5. As a result of analyzing the correlation among variables to identify the multicollinearity before testing the hypotheses, the variance inflation factor (VIF) of each variable was between 1.000 and 2.512, well under the threshold of 10, and therefore there were no multicollinearity problems. The model fit size of the path model was 0.629, which was higher than 0.10 (low) and 0.36 (medium) (see Table 5 and

Table 6. Correlation analysis of research variables.

	IQ	SQ	UV	EV	UE	UF	ET	AT	IT
IQ	0.952
SQ	0.632	0.883
UV	0.461	0.452	0.824
EV	0.361	0.255	0.256	0.799
UE	0.794	0.665	0.543	0.432	0.867
UF	0.564	0.556	0.500	0.346	0.667	0.838
ET	0.652	0.602	0.417	0.452	0.625	0.632	0.813
AT	0.289	0.156	0.140	0.227	0.172	0.228	0.238	0.895
IT	0.375	0.421	0.224	0.186	0.283	0.357	0.267	0.192	0.798

Note: IQ = perceived information, Quality SQ = perceived service quality, UV = utilitarian value, EV = hedonic value, UE = perceived ease of use, UF = perceived usefulness, ET = perceived aesthetics, AT = attitude toward use, and IT = use intention. The loading diagonal shows the square root of the AVE of each construct.

).

5.3. Validation of the Structure Model

The structure model we used to test the hypotheses is summarized in Figure 4 and

Table 7. Results of hypothesis testing for the research model.

Hypothesis	Path	Path Coefficient	t-Value	p-Value	Accepted or Rejected
H1	Perceived information quality (IQ) > Attitude toward use (AT)	0.145	1.826	0.032	Accepted
H2	Perceived service quality (SQ) > Attitude toward use (AT)	0.072	0.921	0.178	Rejected
H3	Utilitarian value (UV) > Attitude toward use (AT)	0.133	1.793	0.039	Accepted
H4	Hedonic value (EV) > Attitude toward use (AT)	−0.042	0.746	0.273	Rejected
H5	Perceived ease of use (UE) > Attitude toward use (AT)	0.289	2.945	0.008	Accepted
H6	Perceived usefulness (UF) > Attitude toward use (AT)	0.147	1.835	0.03	Accepted
H7	Perceived aesthetics (ET) > Attitude toward use (AT)	0.094	0.946	0.161	Rejected
H8	Attitude toward use (AT) > Usage intention (IT)	0.559	14.148	0	Accepted

. Below, we demonstrate how we derived the path coefficients estimated after analyzing the validity, reliability, and correlation between the factors. Generally, the hypotheses are tested using t-values, and we have accordingly applied this method in this study. The results of the structure model analyzing the causal relationship among latent variables are shown in Figure 4.

According to the results, among the variables that have an independent relationship with attitude toward use, information quality was accepted with a p-value of 0.05, a path coefficient of 0.145, and a t-value of 1.826; utilitarian value was accepted with a p-value of 0.05, a path coefficient of 0.133, and a t-value of 1.793; ease of use was accepted with a p-value of 0.01, a path coefficient of 0.289, and a t-value of 2.945; and usefulness was accepted with a p-value of 0.01, a path coefficient of 0.147, and a t-value of 1.835. Service quality, hedonic value, and aesthetics were rejected with p-values of 0.05 and higher and t-values below 1.645. The relationship between attitude toward use and usage intention was accepted with a p-value of 0.001, a path coefficient of 0.559, and a t-value of 14.148 (see Table 7).

6. Conclusions and Implications

6.1. Study Results

This study sought to identify the design attributes of mobile banking services that are gradually advancing and becoming more popular, and empirically analyzed the psychological mechanisms behind the intention to use these services. In doing so, this study provides insights that may be useful for firms, designers, and planners seeking to optimize mobile banking services.

The results of this study can be summarized as follows.

First, among service design attributes, practical content attributes that users can perceive, such as perceived information quality or utilitarian value, may positively affect user attitude toward the service. Attitude can determine the user’s service use; that is, users may differently engage a mobile banking service based on how practical, beneficial, and valuable they think its contents and information actually are [53]. When planning designs, designers must be able to closely investigate the users, distinguish what information should be provided, and continuously develop new information and services that benefit customers.

Second, this study empirically proved that attributes related to user-centered design usability, such as perceived ease of use or usefulness, are essential elements in service design. In particular, KakaoBank is enhancing the user experience by offering various convenient features that have not yet been offered by existing banks, such as tools for sending cash as a gift (e.g., for congratulations or condolences), by linking with a powerful platform service called KakaoTalk. Therefore, as with UX design that emphasizes user experience, mobile banking service design must be studied from the perspective of the actual users [4], and it is absolutely necessary to constantly develop new methodologies in addition to those that require touchpoints with users, such as user journey mapping, focus group interviews, and user tests.

Third, perceived service quality related to trust turned out not to be much of a consideration in mobile banking service design. This may be because trust already underlies the nature of banking services and the general public is accordingly not very concerned about security in the banking sector.

Fourth, users are not really concerned about perceived hedonic value due to the nature of mobile banking services. This may be because banking tends to attach more importance to tangible benefits than fun. However, new hedonic services, such as those offered by KakaoBank and similar mobile banking services, are appealing to customers [7]; this indicates that the hedonic elements in this study were rejected due to the limited age range of the participants. Therefore, it is necessary to study how different age groups feel about these hedonic elements in mobile banking in future research.

Finally, although perceived aesthetics are generally considered essential to design, the users in this study did not give them much consideration. This may be because banking attaches more importance to practicality than aesthetics and because UX design most highly values user-friendly designs. However, new mobile banking services are continuously enhancing their aesthetic features, and the aesthetic standard for mobile banking has accordingly increased. Considering that designs are being standardized according to the increased standard, different results may be obtained by more specifically subdividing the samples.

6.2. Implications, Limitations, and Directions for Future Research

The implications of this study are as follows:

First, design studies currently tend to focus on practicality and, thus, research on theoretical attributes that affect design is lacking. In response to this gap, this study broadened the scope of existing research by applying the TPB, which is commonly used in business administration, economics, and psychology, to mobile banking service design. User-centered design is becoming more important and popular across social, economic, and cultural realms, and services are accordingly advancing rapidly. In modern design, theories about users’ psychological tendencies are applied in various fields, such as those concerned with product, space, visual, service-based, and UX designs according to the user-centered, on-demand trend. Thus, in-depth studies on this topic are absolutely necessary.

Second, this study empirically discovered four mobile banking service design attributes (perceived information quality, perceived utilitarian value, perceived ease of use, and perceived usefulness) affecting user usage intention and internalized them into a theory. Since design trends constantly change to keep up with the rapidly changing times, these attributes have been addressed more in practice than in scholarship. While it is difficult to establish academically, internalizing and establishing these attributes based on theory may encourage the development and use of different design factors across many fields of design. Aside from the four service design attributes we highlight, other attributes are likely to emerge in response to changing social, economic, cultural, and technological conditions, which is why additional research must be conducted in the future.

Third, this study shed new light from a design perspective on financial services that are gradually advancing and growing in the era of the Fourth Industrial Revolution—represented by mobility, fintech, and big data—and articulated new possibilities for service design. Today, various finance-related services, such as those related to credit cards and securities, are emerging; in response to these changes, design circles must train and develop designers specializing in finance. If effective design can create new value through these services, it can drive growth during the Fourth Industrial Revolution. Finally, by empirically classifying the importance of different service design attributes, this study reveals which attributes designers should concentrate on in their work. Moreover, as this study reconfirmed the importance of user-centered design (an essential element of UX and service design) and empirically identified and validated additional factors of strong service design, it lays a foundation for the development of more in-depth analytical methodologies for users. Ultimately, service designers and planners can apply the results of this study to advance user-centered services.

The limitations of this study and the future research directions highlighted by this study are as follows:

First, this study may not have revealed all service design attributes worth noting. For example, the advancement of artificial intelligence (AI) and financial knowledge may be giving rise to new attributes; accordingly, it is important to continue to try to identify new design attributes. Second, this study has limitations in terms of its sample. In particular, considering different ages and genders may have produced different results for hedonic value and aesthetics. Moreover, our survey included many users of Internet-only banks, such as KakaoBank, and Toss Bank had not yet been launched when we conducted the survey. Meanwhile, relatively little data were available on mobile banks other than KakaoBank, which limited the survey in terms of equivalence. Additionally, the results may vary depending on whether participants exclusively use KakaoBank for mobile banking services or also utilize other banks concurrently. Moreover, the perceived utilitarian and hedonic values were not assessed through direct user testing. Future studies must make up for these shortcomings in constructing their samples and should use big data analytics and user tests. Furthermore, research on attitudes towards mobile banking also exhibits qualitative characteristics. Consequently, future studies should employ qualitative research methodologies, such as user interviews and focus group interviews [55]. Finally, unlike the financial circles that have historically been conservatively operated, Internet-only banks offer services characterized by rapidly changing trends, and thus different studies may yield different results depending on when they were conducted—since we conducted the survey we report in this paper, the marketing and operating activities of Internet-only banks have evolved and been integrated with other online services. Moreover, because the Korean government is also quickly changing its financial policies, future studies should adopt different research methods (e.g., big data or unstructured data).