Perceived Mental Beneﬁt in Electronic Commerce: Development and Validation

: There is no denying that electronic commerce has brought many beneﬁts to consumers. In the competitive market, capturing the beneﬁt that customers perceived will be the best way for the sustainability of online businesses. However, in the context of increasing human life quality, re-examining the beneﬁcial dimensions of electronic commerce (e-commerce) is a necessity. This study aims to develop and validate a perceived beneﬁt scale of e-commerce concerning the mental viewpoint. The qualitative research and quantitative research method are used according to the development and validation procedure proposed by Churchill in 1979. The research result indicates that the perceived mental beneﬁt of online shopping is in the second-order concept of four dimensions, including perceived shopping enjoyment, perceived social interaction, perceived discreet shopping, and perceived control. Some research and managerial implications are proposed.


Introduction
The popularity of the Internet and the development of increasingly user-friendly, easier-to-use technology devices, are making significant changes in consumer behavior.The Internet has become not only a channel of communication and information sharing, but also a useful means for a customer to conduct commerce transactions, and connect to other buyers and sellers quickly and conveniently [1].The use of the Internet to conduct transactions is called by many names such as electronic commerce (e-commerce), or online shopping.In Vietnam, recognizing the benefits that e-commerce brings, more and more consumers are choosing this method to shop instead of traditional shopping.The scale of the business to consumer (B2C) e-commerce market is continuously expanding, with the average revenue growth rate of approximately 30% per year from 2014 to 2017 [2].This development shows that B2C e-commerce in Vietnam has become a popular shopping option and a new trend in consumer shopping activities.Therefore, this development is also an opportunity for businesses to achieve better efficiency and sustainability in business.
Shopping through online channels brings many benefits to consumers, such as the saving of resources, independence of time and space, and more choice [3].However, consumers also face many barriers, such as trying to assess the quality of the product before buying, the risk of personal information, or financial loss related to payment [4,5].These issues are indispensable risks in online commerce and are considered as the main barriers for consumers when choosing this shopping option.In this context, the assessment of customers about the perceived benefit and perceived risk, which they get in online trading, is a critical factor that can help consumers overcome pressure from the above risks to conduct shopping transactions [6].Online businesses must be able to identify the interests or reasons for consumer behavior.The benefit that makes customers to satisfy their needs and desires is called purchasing motive.Rational, emotional, and patronage motives are three common motives in shopping [7].Therefore, in the context of research on online shopping, the perceived benefit is the primary motive to push the shopping behavior.
Sheth [8] states that there are two parts of shopping motives, including functional needs and nonfunctional wants.In particular, functional needs are related to time and place, and possession needs, which are functional benefits.Customers are also engaged in their shopping behavior by non-functional desires related to social, emotional, and epistemic values, which are considered to be more related to psychosocial benefits.As people's life quality grows, their need for life is higher and higher.According to Maslow [9], human needs are increasing from basis to advanced (from material to spiritual needs).For a business to succeed it must satisfy all levels of customer need [10].Delafrooz et al. [11] pointed out that the perceived benefits include three types of functions, entertainment, and symbols.The benefits of e-commerce can be categorized as functional or hedonic, or as both of them.A functional benefit refers to the functionality, tools, and practicality of a purchase, while the hedonic benefit refers to the products of aesthetics, experience, and entertainment [12].However, studies of the benefits that e-commerce show fragmentation, due to only mentioning a few functional benefits of online shopping activities, such as convenience, choice, and the quality of goods [3,13]; or by the general focus on the hedonic and symbolic aspects, without elaborating on the mental aspects of e-commerce [14][15][16].Consequently, developing and validating a scale to measure the perceived mental benefit based on achieving positive emotions and psychology when buying online is a contribution to the theory of consumer behavior; it is necessary to develop the theory of emotion as the focus to be able to explain consumer behavior better, in line with the proposal of Pappas [17].
The remainder of this paper will cover the following literature review; research methodology, research results, discussions, and conclusions.

Perceived Mental Benefit
The perceived benefit is a positive result due to a specific action [18].The total benefit of customers includes the economic, functional, and psychological benefits that customers expect from a particular seller based on the products and services provided [10].Consumer perceived benefit is created by advantages, including the utilitarian, hedonic, and symbolic benefits from online shopping [11].Table 1 shows the dimensions of the perceived benefit.Forsythe, Liu, Shannon and Gardner [3] pointed out that perceived benefit indicates what customers gain from online shopping.In other words, Ko et al. [19] claim that perceived benefit is consumers' belief that they can shop at any time without any difficulties or interruptions in the shopping process.The perceived benefit of online shopping can be measured from the product satisfaction and the convenience of online shopping [3].According to Park and Kim [20], this benefit is considered to be the belief of consumers when they feel an online transaction is much better than other online transactions.The perceived benefit of shopping on the Internet is significantly associated with attitudes toward online shopping and intentions to shop online [21].
Emotion is a mental state of readiness arising from a cognitive assessment of events or thoughts; there is a phenomenal tone, which is accompanied by physiological processes often expressed in gestures, postures, and facial features, and which can lead to specific actions to affirm or respond to these emotions, depending on the nature and meaning of them to the person who has them [22][23][24].Cognitive psychology is a branch of psychology that specializes in the activities related to mental processes such as cognition, thought, language ability, memory, problem-solving, and creativity that accompany human actions [25].Hansen [26] defines emotions as a response to a stimulus, and in the online context, stimulation will be the e-commerce page elements that bring in customers' contact and purchase.Research results indicate that the result of cognitive and emotional processes is the development of an individual's attitudes and beliefs.The hedonic aspect is perceived as the emotional benefit that becomes the antecedents of the attitudes and behaviors of consumers in the context of e-commerce [27,28].The emotional aspects of buyers, including those related to identifying a need, seeking information, evaluating options, making purchases, and post-purchase satisfaction, can be crucial in different stages of the buying process [29,30].Therefore, this study concludes that the perceived mental benefit is the benefit of positive psychology, i.e., the emotions that a customer has when shopping online.

Theoretical Background
This study focuses on analyzing the mental benefit of online customers, including the hedonic, symbolic, and psychological benefits that customers achieve in the e-commerce transaction.The study of perceived mental benefit is mainly based on the hedonic consumption theory [31,32], the online flow theory [33], and the self-determination theory [34].
The process of hedonic consumption promotes behavior, influences decision making, and is essential to the survival of the individual.Most human behavior tends to seek exciting experiences both in the short-term and long-term, as well as trying to avoid unpleasant or painful experiences.The perceived hedonic value helps guide people toward behaviors to be involved with and behaviors to avoid [35].In general, it can be mentioned that there are two types of hedonism, including psychology and philosophy.Following the philosophical approach to achieving the highest level of satisfaction is everyone's goal.According to the psychological approach, hedonism can be explained by motivation or benefit.People work to achieve the things that they like or which satisfy them, and tend to act for hedonic reasons and work for them.Theories of hedonic consumption can be divided the hedonist into two different categories.Psychological hedonists believe that all agents act for their benefit, while standard hedonists argue that all actors have a reason to maximize their hedonic value, either for themselves or for all sentient beings.Psychological hedonism is also called the principle of joy.This consumption is closely connected with the multi-dimensional sense to get the psychological benefit finally.In other words, this is a unique kind of consumption that attracts many human senses such as sight, smell, taste, hearing [31].Holbrook and Hirschman [32] pointed out aspects of hedonic consumption, including mental structure, product class, product usage, and individual differences.They believe that the popularity of mental structures plays the most crucial role in the whole consumption behavior.
The theory of flow is one of two theories of internal dynamics developed according to the positive psychological model [36].Flow is an entertaining and vital structure that has been widely recognized as having a high impact on user behavior on information systems [37].Flow is an essential component of enjoyment and an all-encompassing feeling in acting with full participation.In the state of flow, consumers feel easy while time-consuming, and perceive that this experience stands out as extraordinary compared to daily activities [38].Flow is a continuous variable, and different levels of flow can occur, from none to the state of full emotion [39].Online flow is the state that occurs during navigation when transacting online.It characterized by a seamless feedback chain facilitated by machine interaction, the enjoyment, accompanied by a loss of self-awareness, and self-reinforcement [40].Creating a state of flow will bring many competitive advantages to online business.Many marketers are confident that consumers will buy more online if they enter a flow state.Therefore, the business encourages cohesion and constant access by providing online features (e.g., online games, market information, instructional information) in order to create flow while the potential customer is visiting the e-commerce site.
The self-determination theory is an approach to motivation and personality in a social context, as studied by Deci and Ryan [34].The main content of the self-determination mentions internal motivation, which refers to starting an activity for exciting and satisfying experiences, as opposed to performing an activity to achieve an external goal (external motivation).Three basic types of psychological need are competence, relatedness, and autonomy, which meet internal motives and are associated with actions to achieve a non-action-related outcome [41,42].The competence need is the ability to control the outcome or experience.The relatedness need has related interaction with and connection to others.Moreover, the autonomy need is causal agency of one's own life.Motivation is essential in the real world because of its results.Besides, motivation will lead people to act in different ways to achieve what they want.People can be motivated because they value activity or have a robust outside impetus.The study identified internal motivation as associated with behavior performance by the interests directly related to the action and not by an irrelevant result.
Although these theories were presented nearly 20 years ago, it is still valid and applicable to the current society, especially in behavioral analysis and customer psychology.Many recent studies show that functional attributes are no longer exclusive to promote online purchases; in fact, as e-buyers become more experienced, they are increasingly seeking online mental benefits such as the user interface that makes shopping enjoyable [43], online relationship or interaction [44], controllable behavior, and discreet shopping [34].Therefore, the state of flow is part of the mental benefit customers feel when they shop online.In short, the theoretical review shows that motivation is the main component that leads to the behavior of every human being.In the e-commerce environment, these theories can be applied to analyze the decision to choose online shopping for consumers and possibly to explain that customers who buy online will be influenced by not only external forces but also internal motivations of feelings of mental benefits in shopping online.

Perceived Shopping Enjoyment (PEB)
The consumer will look for several situations, such as entertainment, sensory stimulation, excitement, imagination, and fun [32].The enjoyment is a mental aspect with many motivations existing as a shopping goal [45], or an interesting emotional perspective on shopping as leisure [46].Perceived shopping enjoyment can be defined as the level of entertainment and comfort, in addition to performance results [47].Enjoyment can occur not only in traditional shopping but also in the online context [48].Beatty and Ferrell [49] said that consumers enjoy shopping when they feel free and find the shopping process to be enjoyable and fun.In the online market, some vendors have more innovation with more motivation to help consumers increase the shopping experience.Hence, enjoyment is defined as the excitement by trying new experiences in shopping [3].Perceived shopping enjoyment is an important structure in the study of online consumer behavior and has an essential impact on customer attitude and behavior on e-commerce [50].

Perceived Social Interaction (PSB)
People have five types of need, including physiology, safety, love and belonging, esteem, and self-actualization [9].Love and belonging is the high level of need, which is mentioned as friendship, intimacy, trust, and acceptance, receiving and giving affection, as well as a sense of connection.The theory of social constructivism was formulated by Vygostski [51], which added the concept of social interaction, which means that learners interact with others to construct their knowledge.
Online shopping is a process with many benefits but also potential risks for consumers.Buyers need to have certain knowledge to avoid the perceived risks.Learning through social interaction with other buyers is one of the ways to understand the buying process and experience in purchasing goods and services online.Learning is a cognitive development process formed by social interaction [52].Furthermore, the demand for friendship is increasing rapidly, and customers can easily connect as the virtual world develops.Zhang and Hiltz [53] also argue that people who come to virtual communities are not just seeking information or knowledge and problem-solving; they also expect to meet others and seek support and friendship.Indeed, people believe that virtual worlds are a useful way to develop their social relationships.Social interactions are sometimes referred to as non-market interactions to emphasize the fact that they are not regulated by the pricing mechanism [54].Therefore, the perceived social interaction becomes a benefit related to the psychology of the online customer.

Perceived Discreet Shopping (PDB)
An individual has a right to privacy in a situation involving others, meaning that he or she is protected from intrusion, interference, and access to information by others [55].When the customer is naturally protected or prevented from intrusion and access by others, the customer will have privacy.Shopping locations and shopping methods are related to the privacy of customers [56].Many consumers are uncomfortable or embarrassed when buying certain products from a public retail store, i.e., sex products, feminine products [57].Gupta et al. [58] define discreet shopping, meaning consumers buy what they need privately, and others do not know what they buy.Anonymity and discreet shopping are the benefits of online shopping for customers [59].Discreet shopping on the Internet is described by several conveniences, ease to suit busy work and effective solutions for people who want to buy sensitive products, but they dare not come to physical stores [60].Therefore, privacy and anonymity may be the most differentiating factors from online and traditional shopping.Therefore, perceived discreet shopping is a great benefit in that consumers take advantage of buying online instead of buying in traditional stores.

Perceived Control (PCB)
Perceived control of an individual's life is one of the most explored factors in psychology.Control concepts include self-efficacy [61] and perceived behavioral control [62].Behavior is affected by an individual's ability to perform one's behavior [50].Besides, several previous studies have demonstrated the positive effects of perceived control on people who are aware of their situation or expected results [63,64].These advantages help customers feel more confident and better in control of their shopping process.Studies show that the effects of life's events and sufferings can be significantly reduced by perceived control [65].When analyzing perceived control in online services, Godek [66] outlined two factors, that are customization and personalization.Companies have started using new communication technologies to implement collaborative strategies that are tailored to each individual, thereby creating more favorable conditions by creating a match between consumer preferences and products supplied companies [67].In e-commerce, individuals can easily receive ads tailored to the need of suppliers when providing information on e-commerce sites or exposing information on social networking sites; this is the concept of personalization.At the same time, as technology develops, customers can create and customize the product that meets their need.Franke et al. [68] studied the perceived benefit of a self-customized product, claiming that user trust and satisfaction can be generated by offering by consumer customization.Therefore, the perceived control stemming in this study is a factor that influences the mental wellbeing of the clients.

Scale Development and Validation
This study utilizes the common and standardized scale development procedure of Churchill Jr [69], that have been used in many scale development and validation studies.The process is presented in Table 2.

Item Generation
A scale must be accurate, which can be achieved by combining or removing items from its structure [69], and the measuring items should be created after a review of the previous literature.This study evaluated previous studies, such as theoretical theory in psychology, marketing, and e-commerce, the online flow theory, and the self-determination theory, for research to gain insights into the perceived mental benefits of online shopping.
In social science research, differences in the culture and economic levels among different countries can cause differences in the measurement scale.In this study, most of the concepts incorporated in the research model of this topic have been studied and tested in developed countries, whose economic environment is not similar to Vietnam.Therefore, when developing scales to measure concepts in the model in a new context, the focus group discussion technique will create and adjust the mental benefit scales to suit the country's specific environment, as well as clarify the differences of opinion among members when discussing groups [70].The length of the discussion ranges from 90 to 120 min.The chair of the discussion records the discussion.Two Master's in Business Administration (with marketing-oriented research) are invited to conduct coding the items based on the content of the discussion.They work independently during listening and coding the measurement indices.After that, they discuss together the differences or suitability for an analytical unit, and agree on the suitability of the units to include in the next analytical process.

Initial Purification
This study used the content analysis to organize the data from the item generation step into different groups [66].Hence, this research used thematic content analysis to find out and explain the insights of customers about the mental benefits in an e-commerce context.Five different experts, including three experts in online marketing, e-commerce, and two PhDs in business administration, checked the list of items.Guided by considerations of surface validity, this committee has fully assessed all items.Then, to avoid issues of illegal content and ambiguous words, they are required to scrutinize each item.All of them were asked to evaluate each item in a list carefully, based on three response options, i.e., "very relevant," "slightly relevant," and "very irrelevant" [71].This process is the phase of content validity check [72].This result of this process leads to the creation, justification, and elimination of some items.The remaining items are considered for the next phase of the process in Table 2.

Scale Refinement (Study 1)
The next step is shaping the scale by exploratory factor analysis (EFA), assessing the internal reliability (Cronbach's alpha), using first-order confirmatory factor analysis (CFA), and assessing the reliability and the validity of the construct.The EFA is an analysis technique that shortens a set of many observed items into fewer factors that still contains most of the information content and statistical significance of the set of original items.The Cronbach's alpha confirms the level of all items in a construct, and has measured this construct.The CFA analysis helps to clarify a set of four evaluation criteria: (1) unidimesion; (2) reliability of the scale; (3) convergent value; (4) discriminant validity [73].

Scale validity (Study 2)
The purposes of the final phase include (1) confirming the measurement model generated from the first dataset; (2) assessing the generality of the perceived mental benefits; and (3) checking this factor structure and scale suitability in the nomological validity.In order to validate the scale, the study carried out the second-order CFA and tested the relationship of the perceived mental benefits with its consequences, including online trust and hedonic value with the second sample to assess the consistency of the basic structure with previous studies [69].

Sample and Data Collection
This study uses a mixed research method, combining qualitative research and quantitative research to achieve research objectives.In qualitative research, the study carried out group discussions with 11 customers who know e-commerce and consumer behavior (white-collar workers, lecturers, students) in order to filter out the items.Some of the items were derived from previous studies.E-commerce has grown in developed countries in the world, but in Vietnam and developing countries, this is a relatively new method of purchase; most customers still prefer traditional commerce (traditional markets and supermarkets) more than e-commerce.It is not difficult to identify consumers who have online shopping experience; however, choosing savvy customers and evaluating the mental benefits in e-commerce is not easy.Therefore, the selection of respondents in group discussions must be made carefully in order to ensure credibility.Neuman [74] recommended that the snow-ball sampling method is an excellent sampling method to ensure reliability.The average age of the member in group discussions ranged from 18 to 45 years old, and they often buy online (more than three times per week).
The quantitative study included two studies, one used to refine the scale (Study 1), and the other used to confirm the scale (Study 2).The purpose of this Study 1 is to refine the measurement tool based on the psychological attributes, and it is conducted via an online self-administered questionnaire in the purposive sampling method.The sample size is 300 participants, including MBA and Ph.D. students of Business Administration and Information Technology in the Industrial University of Ho Chi Minh City (IUH).The author is a lecturer in IUH, and so it is convenient to collect the data for Study 1 in IUH, and the IUH is one of the most prominent universities, in which the number of students is about 50,000 students per year.The Master and Ph.D. students in Business Administration and Information Technology Major at the Industrial University of Ho Chi Minh City were trained in the subjects of electronic commerce, as well as electronic marketing, and so they have an understanding not only of the practice but also of the theory in electronic transactions field.The response rate of this survey is 92%; 276 samples can be used for further analysis.The research sample descriptive is showed in Table 3.
Data will be recollected to validate the scale in the Study 2. The e-commerce customers are aged 18 years and over, whose occupation is students, white-collar workers, and lecturers, because according to the Vietnam E-Commerce White Paper 2019, these occupations account for 92% of the total number of customers who buy online [75].In Study 2, respondents were collected in four major cities, and the province had the highest e-commerce index in Vietnam, including Ho Chi Minh City, Hanoi City, Da Nang City, Hai Phong City, and Binh Duong province [76].These occupations are often shopping online and have a good awareness of e-commerce.The set of questionnaires to survey is 450; after the screening, the remaining is 439.The sampling method was a non-probability purposive method.

Scale Measurement
All of the 38 items after the group discussion in Study 1, and 19 items after the scale refinement stage have been added to the questionnaire used for the survey.For the survey questionnaire, these items are used to assess the extent to which respondents' agreement is ranked on a five-point Likert scale from 1 (totally disagree) to 5 (totally agree).This study examines the theoretical value of the perceived mental benefits relating to online trust and hedonic value in online shopping.The scale of the research structures is applied from previous studies; for example, the hedonic value includes four items [77], and the online trust includes five items [78].

Item Generation
The study conducted a literature review to identify the commonly used observation variables in the study of perceived mental benefits and the group discussion results also added a number of observable variables appropriate to the context of social networking technology, Web 2.0, and Technology 4.0, such as "ease of exchange information", "feel privacy to search for information without anyone knowing", "not afraid to buy discounted products", "find the product easily based on the information provided", "does not require much effort as suggested by the site" [68,79], "not feel afraid to ask about products but did not buy", "not ashamed to buy sensitive items" [80,81].Filtering, addition, and modification activities were conducted.Moreover, evaluating the content validity creates the process of screening the items based on having some meaningful criteria of the perceived mental benefit concept.The items have the same content; or merely describe psychological states rather than mental benefits (concentration, curiosity, or visual attraction); or do not fit the context of online purchases (challenge).Moreover, the customers in the discussion have omitted several items that show or tend to express satisfaction (good, satisfied, better).The result generated 45 items related to psychological and emotional benefit of shopping online.

Initial Purification
Three Doctors of Marketing took part in the inter-rater reliability test.Kassarjian [82] pointed out that 80 percent or higher of the agreement ratio of coding decisions is reliable.The result of the final coding (94 percent for the initial scale) is the pool of 38 items representing the perceived mental benefit in e-commerce (Table 4).Thirty-eight items have been added to the questionnaire used for the survey.For the survey, these items are used to assess the customers' agreement with a five-point Likert scale from 1 (totally disagree) to 5 (totally agree).When shopping online, I am not ashamed to buy sensitive goods/services.PMB37 I feel free to search for information when shopping online without anyone knowing.PMB38 I am not afraid to purchase discounted products/services on e-commerce sites.
Note: *: The items are eliminated in exploratory factor analysis (EFA); **: The items are eliminated in Cronbach's alpha.

EFA and Cronbach's Alpha
In the EFA, this study used the Principal axis factoring, and the Promax rotation method because the method reflects accurately about data structure [83].The criteria of EFA, follow the research of Hair, Anderson, Babin and Black [73], include:

•
Although factor loading values greater than 0.5 • 0.5 ≤ KMO ≤ 1, and Bartlett test has the sig.< 0.05 • Cumulative of variance is higher than 50% with an Eigenvalue which must be greater than 1.0 The results of EFA, after six repeats in Table 5, show that the observed items are extracted into eight constructs, with the total variance extracted of 65,693% (>50%), and the eigenvalue is 1.066 (>1.0).The KMO coefficient = 0.91 (within 0.5 ≤ KMO ≤ 1) and the Bartlett test with sig.= 0.00 (<0.05).All the factor loadings values in the research are greater than 0.5 (the minimum factor loading value is 0.584).Seven items were excluded from the study (PMB6, PMB8, PMB10, PMB17, PMB23, PMB26, PMB33).Summary of the construct for testing reliability is as follows:  The reliability assessment of the newly discovered construct shows that the first four contracts are valid, with the Cronbach's alpha coefficient more significant than the threshold of 0.7; the smallest correlation coefficient of variables in each scale group is higher than the threshold of 0.3.The rest construct is not valid because the Cronbach's alpha does not meet the threshold.The results of the reliability assessment are shown in Table 6.The result of the EFA and the reliability assessment show the perceived mental benefit in the context of e-commerce, including four constructs with 19 items.Based on the theory as well as the results of the discussion with five experts, the study has shaped the scale of perceived mental benefit, as shown in Table 7.
Four dimensions of perceived mental benefit in e-commerce, which is the high order concept as Figure 1, can be named and explained as: The unique thing about e-commerce is to give me the ability to design everything PCB4 Four dimensions of perceived mental benefit in e-commerce, which is the high order concept as fugure 1, can be named and explained as: Construct 1 includes six items named "perceived shopping enjoyment," which indicates that customers feel joy, excitement, experience and feel the entertainment Construct 2 includes five items named "perceived discreet shopping," which indicates peace of mind during the online shopping process when shopping behavior or shopping products are not disclosed or seen by unrelated people.
Construct 3 includes four items named "perceived social interaction," which involves having a customer build knowledge and relationships through online shopping.
The construct 4 includes four items named "perceived control," which describes how customers are aware of their control over the online system, as they may be able to propose suitable products, design their products, services, or co-create.In the first-order CFA the maximum likelihood is used to test the relationship between the items and constructs.According to Steiger [84], a measurement model is the best when it meets these criteria: (1) chi-square/df index (CMIN/df) ≤ 2, in some cases, CMIN/df ≤ 3 [85]; (2) goodness-of-fit  The unique thing about e-commerce is to give me the ability to design everything PCB4 Construct 1 includes six items named "perceived shopping enjoyment," which indicates that customers feel joy, excitement, experience and feel the entertainment Construct 2 includes five items named "perceived discreet shopping," which indicates peace of mind during the online shopping process when shopping behavior or shopping products are not disclosed or seen by unrelated people.
Construct 3 includes four items named "perceived social interaction," which involves having a customer build knowledge and relationships through online shopping.
The construct 4 includes four items named "perceived control," which describes how customers are aware of their control over the online system, as they may be able to propose suitable products, design their products, services, or co-create.
Figure 2 shows the unidimensionality of all constructs in the perceived mental benefit scale.The result of CFA in Table 8 pointed out that all criteria are satisfied; specifically: degrees of freedom of 146, Chi-square is 181.752,CMIN/df is 1.245 (<2).Moreover, this model is suitable for market data because both the GFI (0.937), TLI (0.990), and CFI (0.991) are greater than 0.9.Moreover, the RMSEA is 0.03 (<0.05).

Assessment of the Validity of the Construct
The assessment of convergent validity aims to confirm that each item represents the construct that it belongs to [86].According to Table 8, all constructs achieved the convergent validity when they meet all criteria including (1) composite reliability (CR) ≥ 0.7 [87]; (2) average variance extracted (AVE) > 0.5 [88]; and (3) the standardized factor loadings (λi) of items in CFA > 0.7 [87].The result of CFA in Table 8 pointed out that all criteria are satisfied; specifically: degrees of freedom of 146, Chi-square is 181.752,CMIN/df is 1.245 (<2).Moreover, this model is suitable for market data because both the GFI (0.937), TLI (0.990), and CFI (0.991) are greater than 0.9.Moreover, the RMSEA is 0.03 (<0.05).

Assessment of the Validity of the Construct
The assessment of convergent validity aims to confirm that each item represents the construct that it belongs to [86].According to Table 8, all constructs achieved the convergent validity when they meet all criteria including (1) composite reliability (CR) ≥ 0.7 [87]; (2) average variance extracted (AVE) > 0.5 [88]; and (3) the standardized factor loadings (λ i ) of items in CFA > 0.7 [87].
Discriminant validity aims to prove a construct that is different from others in the research model [89].It is possible to perform the correlation coefficient between the two constructs that are different from 1.0.The assessment result in Table 9 shows that the correlation coefficients (R) between the constructs are less than 1.0 with the confidence level of 99% (all p-value is 0.000).Therefore, the concepts of PEB, PSB, PDB, PCB archive discriminant validity

The Scale Validity
The process of developing the scale and the process of scale refinement have resulted in four-dimensions of perceived mental benefit in e-commerce.During the development stage, EFA and first-order CFA are done on the same sample.The second-order CFA and the nomological validity is conducted on the second dataset to ensure the reliability of the research [90].The second sample is described in Table 3.

Second-Order CFA
The Second-order CFA model analysis in Table 10 showed a fit on the data set collected.All conformity measures (GFI = 0.950; TLI = 0.981; CFI = 0.983; RMSEA = 0.036) are in compliance with the criteria testing.The results of Table 10 also show that all criteria meet the convergent validity.The scale of four constructs is reliability (CR > 0.7; Cronbach alpha > 0.7; and AVE > 0.5).In addition, the scales also achieve unidimensionality when the errors of items are not correlated with each other.The standardized weight of the first-order and second-order scales in the model are both greater than 0.5 and have a statistically significant p-value (< 0.05); therefore, the perceived mental benefit meets the standard of the second-order concept [83,91].

The Nomological Validity
The nomological validity ensures that the perceived mental benefit is significant in research.Therefore, the study assessed the relationship of the scale of perceived mental benefit with the associated theoretical constructs in the previous researches.Chiu et al. [92] pointed out that the hedonic benefit is the antecedent of the hedonic value in e-commerce transactions.Moreover, the perceived benefit has a positive impact on trust in mobile payment services [93].Therefore, a causal relationship between the perceived mental benefit of an e-commerce site and its results, such as hedonic value and online trust, is tested.These two constructs also test the reliability before being used for assessing the nomological validity of the perceived mental benefit scale.The result of Table 11 shows the reliability of the hedonic value and online trust.The results of Table 12 show that online trust has a good correlation with a perceived discreet shopping (0.435), perceived control (0.406), as well as a high correlation with the concept of perceived social interaction (0.684) and perceived shopping enjoyment (0.680).Similarly, the hedonic value also has a high correlation with the aspects of perceived mental benefit, namely, the perceived discreet shopping (0.636), the perceived shopping enjoyment (0.496), perceived social interaction (0.346), and perceived control (0.687).The high correlation between online trust as well as the hedonic value when shopping online with significant levels of less than 0.05 suggests that the proposed dimensions of perceived mental benefit are valuable in e-commerce.At the same time, it also verifies the nomological validity of the proposed scale according to the criteria given by Shimp and Sharma [94].

Discussions
Firstly, customers find the enjoyment to shop online because they can choose to buy whatever product or service they need even though the product or service is in another country.The perceived shopping enjoyment in this study has many similarities with the benefit of previous studies [95][96][97][98].The enjoyment concept of shopping is seen by customers as a benefit, especially in e-commerce, with the method of buying without going to the store.Shopping online is entirely separate and independent; customers do not have to crowd at markets or shopping centers.Additionally, e-commerce allows customers to discover, select, and shop for all the right products, i.e., customers need to search, click, and wait for delivery.If dissatisfied with the product for the fault of the seller or manufacturer, consumers can return it and try another product.E-commerce is proliferating, major e-commerce sites such as Amazon.comand ebay.com are constantly launching promotions like Black Friday, birthday celebrations, or Flash Sale every hour.Customers are in the mood to wait for the products they need, after ordering the product when it is opened for sale, which creates new psychology for customers in e-commerce.Shopping is the most common way to kill online users' time when they are free, so up to 60% of people who are online but do not know what to do will decide to shop; 47% decided to seek information on products and services which they are interested in [99].Moreover, online shopping is also seen as ways that can help customers overcome feelings of depression or stress in life.Many customers think that surfing online shopping channels and choosing the right designs at home can relieve stress effectively.Shopping is arguably a great stress reliever.Shopping online increases positive effects and helps reduce stress.Somehow people have a belief that if they have more "material," they will feel better.Experts concur that if a person is in a state of stress, he or she should engage in any activity that interests him or her, which will bring about a better mood or feeling.By shopping online, customers can bring positive emotions and regulate negative emotions and stress.Because stress is often accompanied by a lack of interest, participating in online shopping can be an excellent method [100].
Secondly, when life is too busy for work and family, many people ignore social needs and interactions with those around them.Perceived social interaction reflects the theory of need [9], as well as the theory of social constructivism [51].The scale of perceived social interaction is based on previous studies [95][96][97][98]101].The feeling of developing friendships while shopping online is one of the most valuable relationships customers have.Building relationships will help customers gain many different benefits from different friendships.According to Mentalhealth [102], customers can talk with friends confidently about things, which they will not discuss with family.Friendship is an essential element in protecting each person's mental health.Developing relationships will help online customers find a connection, exchange information, and get more information when shopping.Shopping online allows customers to exchange with each other even though they have never met or known each other before.Customers can talk to each other through businesses' social networking sites, online shopping forums, or through comments on products and services of businesses, and on forums such as webtretho.com,for one real example.Traditional forms of e-commerce are gradually turning to social commerce; users can connect to shop together.Many B2C sites, such as amazon.comor netflix.com,provide consumers with a wide range of social contexts and opportunities for interaction, such as product ratings.Using blogs, wikis, discussion groups, and Twitter, e-commerce sites can help customers find and purchase opportunities through referrals or advice from others.
Thirdly, many customers have to worry about traditional shopping because they have to come to the place to buy without any privacy about the purchase process.Online shopping makes it possible for customers to buy without going to the store; customers are also free to search for product or service information that no one can know.This benefit is by the privacy theory of Moor [55].Recent studies by Bhatia, Breaux, Reidenberg and Norton [59], To and Sung [103] show that customers feel the need to have privacy in the purchasing process, and e-commerce meets that for them.Many customers feel embarrassed not to buy a product or service after asking for information from a seller.Many customers even buy the product because they have accidentally asked the seller whether they do not need or like this method.Buying goods online helps customers be confident that as transactions are anonymous, buyers can request information about the product or service at any time without fear of the seller being annoyed when not buying.Another aspect of the spiritual benefit of online shopping is avoiding shame, and shame when buying discounted products or sensitive products from traditional stores.The utterly private purchase process is one of the factors that helps customers feel the purchase is discreet.
Finally, the development of technology makes e-commerce possible for customers to create "unique" products.The concept of perceived control has been mentioned in TPB theory and is experimented in this model of sensory, mental benefit.The scale of perceived control is also built based on previous research [97,101].Creating products tailored based on their interests and need creates perceived control when making purchases.The most typical example is Dell Corporation; customers can customize the Dell product configuration to suit their work need or personal preferences.Designs tailored to individual characteristics will create a product that best suits each person, creating admiration or praise from others about the product when customers use them.Moreover, e-commerce makes it easier and more comfortable for customers to have a personalized feature.Online businesses have a clear understanding of customers through data from social media channels such as Facebook, Instagram, and Youtube."Big data" of the customer is the key for the marketing team to draw the customer persona correctly, and the business will become referrals for their customers.The Amazon e-commerce site knows a lot about customers' buying habits, thereby providing customers with the right product recommendations, or based on the demographic characteristics that customers provide [104].

Conclusions
Through qualitative research including document review, group discussion as well as evaluation of structural and surface validity, the research has developed and validated four dimensions of perceived mental benefit in e-commerce: perceived shopping enjoyment (PEB), perceived social interaction (PSB), perceived discreet shopping (PDB), and perceived control (PCB).These dimensions are consistent with previous theories as to the hedonic consumption theory, the theory of self-determination, social constructivist theory, and the online flow theory.These components express the psychological, emotional benefit when customers choose to buy from e-commerce sites.According to the results of two quantitative studies (n 1 = 276 and n 2 = 439) in order to refine and validate the scale including the results of assessing exploratory factor analysis (EFA), reliability of scale (Cronbach's alpha), first-order confirmatory factor analysis (CFA), the validity of the construct (convergent and discriminant validity), and second-order CFA.Quantitative research results show unidimensionality, ensuring reliability, convergent validity, discriminant validity, and nomological validity of all constructs in the concept of perceived mental benefit.
In order to increase the mental benefit for customers in online shopping, the business should have more suggestions for customers about products that may be related to the products that they find are attractive.Because many consumers think of online shopping as a way they can make their mood better when their feelings are not right, recommending related products will help e-commerce sites retain customers longer in the process of customer shopping.Additionally, this can benefit customers in expanding the selection and purchasing process, giving customers more time to enjoy their buying process and helping to improve their mood.Online business should improve the better quality of product images to enhance the customer enjoyment experience during the buying process.Three-dimensional (3D) pictures can be used, so the customer can see more details about the product.In addition, missing or incomplete representations of the needed information product can lead to product misunderstandings.Hence, the product description should be sufficient to be able to answer customer questions about the product, how to use it, benefits, storage, and resources.The product information on the page can be in multiple layers.If space is tight, a business must have a brief summary or description at the top of the page, with a neat link to add details.In order to improve social interaction on e-commerce sites, businesses can consider improving authentic relationship building between customers through social channels, forums or directly through the e-commerce page in the "Comments and Reviews" section.Another way for online businesses is to switch to social commerce, allowing customers to buy products together at a discount compared to individual purchases, creating link modes when making purchases or sharing information about an item between people with similar goods interests.In addition, businesses should allow their customers to request product/service information or post feedback on an e-commerce site without providing their personal information.Moreover, the business also ensures that they will not provide their customer information; this solution makes customers private when interacting in online shopping.In addition, a business must publish their privacy policies on their e-commerce sites to ensure customer privacy.Finally, electronic retailers should enhance their business applications by giving customers more space to participate in the design process of their own products.Moreover, the online business should develop a system to analyze customer activities to find out the customer's interests, or needs.An online survey is the best solution to get more information about customer behavior for business development.
Despite considerable efforts in the research, however, this study still has some limitations, that may provide an opportunity for further research.Further researches can identify a specific area of online transactions (mobile commerce, social commerce) or specific products/services to create specificity in the construction of a scale.In addition, applying the concept of perceived mental benefit in relation to online trust, perceived value, or research in the field of relational marketing is one of the necessary and practical values in this research as well.

Figure 1 .
Figure 1.The conceptual model of perceived mental benefit.

Figure 2 .
Figure 2. The first-order CFA result of the perceived mental benefit scale.

Figure 2 .
Figure 2. The first-order CFA result of the perceived mental benefit scale.

Table 1 .
The perceived benefit dimensions.

Table 2 .
Process of development and validity of the perceived mental benefit scale.

Table 4 .
The initial pool of scale items for perceived mental benefit in e-commerce.

Table 5 .
The result of EFA.

Table 6 .
The result of the reliability assessment.

Table 7 .
The result of Scale refinement.

Table 8 .
The result of First-order CFA.

Table 8 .
The result of First-order CFA.

Table 9 .
The result of discriminant validity.

Table 10 .
The result of second-order CFA.

Table 11 .
The result of CFA for assessing the nomological validity scale of perceived mental benefit.

Table 12 .
The result of the correlation.