The Effect of Service Quality and Endorser Credibility on Purchase Decision Mediated By Brand Image (Empirical Study: Active Students of Jaya Buana Vocational High School in Tangerang Regency)

This study examines the impact of service quality and endorser credibility on the purchase decisions of prospective students at SMK Jaya Buana, a vocational high school in Tangerang Regency, with brand image as a mediating factor. The research employs a comprehensive design that includes validity, reliability, and hypothesis testing, using structural equation modeling (SEM) to analyze the data. The findings reveal that both service quality and endorser credibility significantly influence purchase decisions, with service quality identified as the most critical contributor. Furthermore, the study demonstrates that brand image plays a vital role in enhancing the effect of these variables on purchase decisions, acting as a powerful mediator. The results suggest that improving service quality and leveraging credible endorsers can significantly boost a school's brand image, thereby increasing student enrollment. This research underscores the importance of strategic management in educational institutions to attract more students by focusing on service excellence, credible endorsements, and a strong brand image.


INTRODUCTION
The development of education in the community is accelerating, and various kinds of community needs to gain abilities, expertise and theories in science for their future needs are juxtaposed with the needs of the industrial world, both goods or services that require specialized, specified and specialized skills so that in the implementation of national education, the government makes vocational schools to support the needs of the industrial world, the creation of a ready workforce use it by having the skills needed in the world of work According to (Kuswana, 2013) vocational education is secondary education that prepares students, especially to work in certain fields, which is then clarified by the opinions of (Utami, 2013) who state that Vocational High Schools (SMK) are educational institutions that aim to provide special provisions and skills, students are prepared to enter the world of work.Vocational High School (SMK) is an education that prioritizes the development of students' ability to be able to work in certain fields, adaptability in the work environment, see job opportunities and develop themselves in the future.In line with Djojonegoro (Yoto, Kustono, Muladi, & Wardana, 2013), vocational education is a strategic program to provide a middle-level workforce.Vocational High School (SMK) is a formal education that has a special training pattern to direct students to become graduates who are ready to enter professionally and participate in the business world or companies.

Electrical Power Installation Engineering 6. Fashion Design
Public trust in SMK Jaya Buana Every year continues to increase, it is marked by more and more residents or school-age students entering Jaya Buana schools.From year to year, the number of students of SMK Jaya Buana has increased very significantly.
The number of students attending SMK Jaya Buana is stable every year increasing significantly, while the increase in students in other schools in vocational schools in Tangerang regency tends to stagnant or even decrease.
The increase in students and trust in SMK Jaya Buana, the author believes that there are reasons or something that the management of Jaya Buana has done in a massive way.To attract many junior high school or MTs students in Tangerang district, they decided to attend SMK Jaya Buana.In the graph, the comparison that interest in attending SMK Jaya Buana with the surrounding SMKs is very high is an interesting phenomenon to be researched, if we refer to the Infrastructure of SMK in Tangerang Regency, the availability and quality are almost uniform with each other, do not have more attractive infrastructure facilities than others, but the magnet who wants to go to SMK Jaya Buana is stronger.
Service quality is the most important key element for a business, whether it creates goods or service products.(Ching Fu Chen, 2008).The concept of service quality can effectively explain the difference between the actual feelings of consumers and the expected feelings after receiving services in the process of service quality delivery.This leads to a service gap between industry and consumers, and proposes a service gap theory model.(Parasuraman, Zeithaml, & Berry, 1988), the quality of service is indicated by the degree of gap between customer perception and their expectations.The 'disconfirmed model hopes' begin with the process of setting expectations and end with the disconfirmation of those expectations with their perceptions that form the basis of the SERVQUAL scale and thus the operationalization of the GAP model.
According to (Ohanian, 1990), Endorser Credibility is the extent to which a source is seen as having expertise relevant to the topic of communication and can be trusted to provide an objective opinion on the subject.According to Goldsmith et al. (2000) Endorser Credibility is the level of consumer trust in sources in providing information to consumers (Kotler, Armstrong, & Balasubramanian, 2023) Brand Image is a name, term, symbol, sign, design, or combination of all of these aspects that indicates the identity of a product or service from one or a group of sellers that distinguishes that product from competing products.A strong brand is built on a positive customer experience that arises from the customer's feeling of using the product or service, (Lemon, et.al 2016in Bernd F.et al, 2023).Customer experience with the brand adds meaning and value to the customer's self, facilitates decision-making and increases brand loyalty (Kumar & Kaushik, 2020).(Schiffman, Wisenblit, & Kumar, 2011), stated that the decision-making process is influenced by the company's marketing business factors (products, promotions, prices and distribution channels) and socio-cultural factors (family, information sources, noncommercial sources, social class, culture and sub-culture).According to (Hawkins et al., 1998), consumers in making purchasing decisions are influenced by external and internal factors.External factors consist of culture, subculture, demographic, social status, referral groups, family and marketing activities.Internal factors consist of: perception, learning, memory, motivation, personality, emotions and attitudes.In the midst of rapid competition in the world of education, the decision to choose a school is important for parents and students.Formal education is one of the needs in acquiring knowledge to realize ideals and desires through teaching.Education is the most important thing for society, especially Indonesia, because with education, it can determine the progress and development of a country.Education in Indonesia starts from Elementary School (SD), Junior High School (SMP)/Madrasah Tsanawiyah (MTs), Senior High School (SMA)/Vocational High School (SMK)/Madrasah Aliyah (MA) to Higher Education.In pursuing education, it can influence the community in making decisions from various alternative options that exist, such as in the selection of schools both from elementary school to college where the choice of this school will help in the formation of personality and attitude and will affect the future for their children.
In choosing a good and right school, of course, it is not an easy thing, this is because of the many considerations or criteria that must be considered in choosing a school, especially in high school high schools, as well as the many school choices that confuse the community, both students and their parents.Then people tend to choose schools because they follow their children's friends.The quality of service and trust in information from the endorser (the person who provides the recommendation) are the main factors that influence the decision, in addition to that, the school's brand image also plays an important role in the decision-making process of choosing a school.Examining the influence of these variables and how Brand Image mediates the influence of service quality and Endoser Credibility on school selection decisions can provide valuable insights for schools in improving their marketing and service strategies.
In this study, the author also reviewed several literature as a basis for developing research to have an overview from another point of view.(Chia Chen Chen & Chen, 2023) conducted empirical research on service innovation, service quality, and customer satisfaction based on the response of consumers who have used security services.From the results of the study, it can be concluded that quality home security service satisfaction has a significant positive effect on service innovation, and also has a significant positive effect on the aspect of service quality satisfaction.This is in accordance with the results of (Chia Chen Chen & Chen, 2023), Ren (2018), Dan Lam et al. (2018).Isnanda et al, 2020 This study explores the antecedents of buying interest and the influence of buying interest on recommendation intention.Based on the discussion in the previous section, the following are some of the concluding points in this study (i) Endorser Credibility has a positive effect on consumer buying interest; (ii) Brand image has a positive effect on consumer buying interest; (iii) Brand loyalty has a positive effect on consumer buying interest; (iv) Perceived quality has a positive effect on consumer buying interest; (v) Consumer buying interest has a positive effect on recommendation intention.(Takaya et al., 2018) examines the Influence of Credibility Endorser, Brand Credibility, Self-Brand Connection on Brand Equity Based on the study and analysis conducted in this study, there is a positive influence of Credibility Endorser on brand credibility, In the second hypothesis there is a positive influence of Brand Credibility on Brand Equity.The credibility of an existing brand and what consumers know can positively affect brand equity.In the third hypothesis, there is an influence of Endorser Credibility on self-brand connection, which means that endorsers that have influence, attractiveness, and trust from consumers, there is no influence of self-brand connection on brand equity, which means that consumers' expectations for a product that is able to describe themselves cannot be represented by the product.There is no positive influence of endorsers' credibility on equity brand, meaning that the high attractiveness of the enduser does not necessarily affect consumers so that it has a positive influence on the brand.The enduser used by Vivo is a multi-talented artist who has a positive image.
Mahiri, 2020 Examining the Influence, Brand Image and Store Atmosphere on Purchase Decisions on Consumers of Village-Owned Enterprises (BUMDES) Mart Banjaran Based on the results of the calculation of the brand image variable on purchase decisions, it is stated that the brand image variable has a positive effect on purchase decisions.

RESEARCH METHOD
A research design is a plan or strategy used by researchers to collect, measure, and analyze data.This design serves as a framework to ensure that research is conducted in a systematic and logical manner, allowing researchers to answer research questions or test hypotheses with high validity and reliability.Research design is a framework, blueprint or plan for data collection, measurement and analysis, which is designed to answer research questions (Sekaran & Bougie, 2016).
The research design describes the details of the methods and procedures needed to obtain the information needed to structure and/or solve research problems (Tjiptono, 2014).A research design is a comprehensive research plan that includes everything the researcher will undertake, from the submission of the hypothesis and its practical implications to the analysis of the completed data.

RESULT AND DISCUSSION
The stages of this research analysis are divided into six stages, namely; (1) Validity test, (2) Reliability test, (3) Good of Fit test (4) Hypothesis test, (5) Path analysis, and (6) Determination Coefficient test.

Instrument Validity Testing
In this study, the validity of the research instrument was tested using the Confirmatory Factor Analysis (CFA) Test.This test is carried out to determine the validity of the construct or to find out whether each indicator can explain the existing construct.The indicators used as a measure of the validity of the research variables are those that have a loading factor of > 0.5 while indicators that have a loading factor of < 0.5 are eliminated from the model.Figure 1 shows the CFA test for exogenous (independent) and endogenous (dependent) variables using the AMOS program.

Reliability Test
In this study, the reliability test of each variable was measured using Cronbach's alpha.Cronbach Alpha is a measure of reliability that has a value ranging from zero to one (Hair, Ringle, & Sarstedt, 2011).The results of the reliability test for each of the variables of this study can be seen in Table 4.8 where five research variables have Cronbach's alpha values between 0.897 to 0.952 which means that all variables have very reliable reliability as a research instrument.

Model Goodness of Fit (GOF) Test
In this study, the Goodness of Fit (GOF) test is used as a reference for whether the research model is acceptable.This test was carried out because the data analysis method used was the Structural Equation Model (SEM) using the AMOS program.SEM is a multivariate technique that combines aspects of multiple regression and factor analysis to estimate a series of dependent relationships simultaneously.In SEM-AMOS there are 33 Cut of Value provisions according to Table 3 which can be used to measure the entire research model to determine whether the proposed model is good.1, the results of the Goodness of Fit assessment have been recapitulated in Table 2. where this research model has eight evaluation of the fit model, so it can be concluded that the research model is fit and can be continued for the hypothesis analysis process.Hypothesis testing is carried out after the research model can be considered fit.While the basis for decision-making is as follows: • If the P value (Probability) > 0.05 or CR < 1.96, then H1 is rejected and H0 is accepted (no effect) If the P value (Probalitias) ≤ 0.05 and the CR ≥ 1.96 then H1 is accepted and H0 is rejected (there is an effect) Hypothesis testing is carried out by looking at the results of the regression weight of the research model.Table 5 describes the results of the estimation of the research model.The following is an explanation of the testing of all research hypotheses referring to Table 5 and Table 6: 1. H1: Service quality has a positive effect on Brand Image.
In Table 5, the P value of the variables SQ = 0.000< 0.05 and CR=6.986 > 1.96, so H0 is rejected and H1 is accepted, which means that SQ has a positive and significant effect on BI.The higher/ positive Service quality will be/ Brand Image 2. H2: Credibility Endorsement has a positive effect on Brand Image In Table 5, the P value of the variables EC = 0.000 < 0.05 and CR = 3.829 > 1.96, so H0 is rejected and H2 is accepted, which means that EC has a positive and significant effect on BI.The higher / positive learning orientation , the higher / positive absorption capacity.

H3: Service quality has a positive effect on Purchase Decision
In Table 5, the P value of the variables SQ = 0.021< 0.05 and PD=2.303 > 1.96, so H0 is rejected and H3 is accepted, which means that SQ has a positive and significant effect on PD.The higher / positive the service quality , the higher / positive the purchase decision.4. H4: Endoser Credibility has a positive effect on Purchase Decision In Table 5, the P value of the variables TO = 0.016 < 0.05 and CR=2.416 > 1.96, so H0 is rejected and H4 is accepted, which means that TO has a positive and significant effect on FP.The higher/positive Endorser Credibility will be, the higher/more positive Purchase Decision 5. H5: Brand Image has a positive effect on Purchase Decision In Table 5 the P value of the BI variable = 0.000 < 0.05 and CR=5.892 > 1.96, so H0 is rejected and H5 is accepted, which means that BI has a positive and significant effect on PD.The higher/positive the brand image , the higher/positive the Purchase Decision 6. H6: Service Quality has a positive effect on Brand Image-mediated Purchase Decisions In Table 5, the P value of the variables SQ = 0.000 < 0.05 and PD = 4.509 > 1.96 so that H0 is rejected and H6 is accepted, which means that SQ has a positive and significant effect on PD.The higher / positive the Service Quality , the higher / positive the Purchase Decision mediated by Brand Image.

H7: Endoser Credibility has a positive effect on Purchase Decision influenced by Brand Image
In Table 5, the P value of the EC variable = 0.001 < 0.05 and PD=3.210 > 1.96, so H0 is rejected and H7 is accepted, which means that EC has a positive and significant effect on PD.The higher/positive Endorser Credibility will be, the higher/more positive Purchase Decision Direct, Indirect and Total Influence The analysis was carried out to determine the magnitude of the direct, indirect, and total influence coefficients of all research variables.Based on Figure 2, the magnitude of the direct influence of SQ to PD is 0.199.Meanwhile, the indirect influence of SQ to PD through BI is 0.379 , so the influence of SQ to PD through BI mediation (indirect) is greater In this case, the Brand Image variable is significant to mediate Service Quality to Brand Image.
Service Quality (SQ) has a significant direct influence, albeit moderately (0.199), on Purchase Decision (PD).This means that improving the quality of service directly will increase the likelihood of consumers making a purchase.The influence of service quality (SQ) on Purchase Dicision (PD) through Brand Image (BI) is much greater (0.379).This indicates that the quality of service not only directly influences the purchase decision, but also indirectly through the formation of a positive brand image.The Brand Image variable proved to be a strong mediator between SQ and PD.

Direct and Indirect Influence Endoser Credibility on Purchase decision through Brand Image
Based on Figure 2, the direct influence of EC to PD is 0.169, and the indirect influence of EC to PD through BI is 0.200 So the influence of EC to PD indirectly or through BI mediation is greater than the direct influence In this case, the Brand image variable is significant to mediate Endorser Credibility on Purchase Decision Endorser Credibility (EC) has a significant direct influence, albeit moderately (0.169), on Purchase Decision (PD).This means that Endorser credibility can directly influence consumers' decision to buy.The influence of EC on PD through Brand Image (BI) is slightly greater (0.200).This indicates that Endorser credibility not only directly influences purchase decisions, but also indirectly through the formation of a positive brand image.
Based on the explanation of the direct and indirect influence between independent variables (Service Quality, Endorser Credibility) on the bound variable (Purchase Decision), the role of the Brand Image (BI) variable is proven to be a significant mediator between SQ, EC and PD.This means that Service Quality, High Endorser Credibility will build a positive Brand Image, and this positive Brand Image is what then encourages consumers to make purchases.

Total Direct and Indirect Influence
Based on Figure 2, the total influence of service quality on Purchase Decision directly and indirectly (Brand Image mediation) is 0.578 While the total influence of Endorser credibility on Purchase Decision directly and indirectly (Brand Image mediation) is 0.369.So it can be concluded that the total influence (direct and indirect) is the largest is Service Quality to Purchase dice, then followed by Endorser credibility to purchase decision.

Service quality has a positive effect on brand image
Service quality has a positive and significant effect on the Brand Image so that Hypothesis-1 is accepted.The higher / positive the service quality , the higher / positive the brand image.This means that the respondents have the perception that the school always tries to provide the best service, meets the needs of students quickly, complaints and suggestions from students are well considered, the regulations in this school do not make it difficult for students, understand what students need and provide appropriate solutions, are given clear information about the products and services they have in the school, and provided with information about the fees that must be paid before starting school, providing a good image for the school In the previous study, (Kim & Kim, 2016) Analyzing the Impact of Service Quality on Brand Image and Brand Defense found that service quality had a positive impact on brand trust, Also in the research of SOOMRO et al., (2022) on Saudi airline customers that service quality has a positive effect on the company's image, there is also a direct influence of the service quality of alliance partners on the brand image is significant.Wiradireja (2023) also obtained research results that show that service quality has a significant influence on brand image.
Thus, Service Quality allows strengthening the company's ability to maintain and reactivate an assimilated or related Brand Image.So the results of this study are in line with previous research which states that Service Quality has a positive and significant impact on the School's Brand Image Endorser Credibility has a positive and significant effect on Brand Image.
Endorser Credibility has a positive and significant effect on the brand image so that Hypothesis-2 is accepted.The higher / positive the Endorser Credibility, the higher / positive the brand image.The results of the processing found that one of the important factors in Endorser credibility is that the figure (endorser) has an attractive appearance, An attractive appearance can attract the attention of consumers (prospective students) and make them more interested in the message conveyed, Consumers tend to identify themselves with endorsers who are considered interesting, thereby increasing trust in the product or brand being promoted.An attractive appearance is often associated with high product quality.
Based on the results of this study, it was found that Endorser credibility has a positive and significant effect on Brand Image The higher the level of Endorser credibility, the higher the Brand image, the more this kind of result is in accordance with previous research that Endorser credibility affects Brand image.In the research of (Gunawan & Daulay, 2023)  endorsement credibility congruence has a positive relationship with brand credibility, From the results of other studies, it is also shown that the Endorsement Credibility variable from J&T Express affects the Brand Credibility variable, Purnama et al., 2015) and it is also emphasized in the pre-research that Endorsement Credibility has a positive effect on Brand Credibility based on this study by using Vivo Smartphone student customers in Jakarta.
For this reason, the school's commitment to continue to use credibility endorsements affects the brand image of the school, so that prospective students or the general public increasingly know and understand what is in school, both physically and activities at school, so as to arouse the interest of prospective students to attend school Service Quality has a positive and significant effect on Purchase Decision Based on the results of data processing related to Service Quality affecting Purchase Decision at SMK Jaya Buana Tangerang Regency, the same thing as the previous study, that Service quality can affect Purchase dice.Previous research conducted by Aditya et al., (2018) views that Service Quality can affect a company's Purchase Decision.However, in the research of Siradj et al., (2023).The results of the service quality research have no effect so it does not support the hypothesis Service Quality is seen as important in schools, schools that always try to provide the best service, provide clear information about the products and services they have in the school, provide information about the fees that must be paid before starting school affect strategic decisions in the company.Service quality is a very valuable asset for a school.By providing the best service, the school will not only attract the interest of prospective students, but will also build a good reputation and ensure the school's sustainability in the long term.So in this study, this service quality has a positive and significant effect on the Purchase Decision so that Hypothesis-3 is accepted.

Endorser Credibility has a significant positive effect on Purchase Decision
The results of the processing of respondent data related to the influence of Endorser Credibility on the Purchase Decision of SMK Jaya Buana show that Endorser Credibility has a significant effect on the Purchase Decision.This means that respondents have the perception that the higher/more Endorser Credibility in schools will significantly affect the Purchase Decision in schools.The respondents in this study consider that Endorser Credibility is needed by companies to increase prospective students to give the Decision to attend school at SMK Jaya Buana (Purchase Decision) This is in accordance with research conducted by Decision Muslim, et al., (2021) that the results of their research that Endorser credibility has a positive and significant effect on Purchase Decision, Also in accordance with Research, HA and Nhat (2019) so that Hypothesis-4 is accepted Brand image has a positive and significant effect on Purchase Decision.
The results of the processing of respondent data resulted in a brand image that had a positive and significant effect on Purchase Decision.so that the higher/more positive the brand image will affect the purchase decision, the higher/more positive.Respondents in this study believe that a good school Brand Image and must continue to be maintained and improved Brand with a positive image can build consumer trust.Consumers are more likely to choose products from brands they trust, Consumers often identify themselves with a particular brand.They buy products not only because of their function, but also because of the values that the brand represents.Brands that have a strong image are often associated with high quality, even before consumers try their products, even Some brands have an exclusive or luxurious image, so buying products from those brands can increase the social status of consumers.
Previous research stated that a brand image can arise after a purchase decision on a product or service from a company which will affect the reputation of a brand or brand image Satu and Kim (2021).Meanwhile, in some ways, the image of a brand or brand image that is already attached to many customers in a certain area or location, will have an impact on the Purchase Decision of the product or service from the brand Ratnasri et al., (2023) In some studies, it is also mentioned that having a brand with a good reputation and is well known to the global community (brand image), the ease of consumers in taking Purchase Decision Susi et al., (2023).until Hypothesis-5 is accepted Service Quality has a positive and significant effect on the purchase decision mediated by Brand Image.
Service quality has a positive and significant effect on the Purchase decision mediated by the Brand image so that Hypothesis-6 in this study is accepted This means that the better the consumer's perception of the quality of the service provided, the more likely they are to make a purchase.means that good service quality will form a positive Brand image in the minds of consumers, and Brand Image This positive is what then encourages consumers to make purchases.
So that the higher / more positive the service quality mediated by the brand image, it affects the decision to attend SMK Jaya Buana (Purchase decision).In accordance with previous research which stated that service quality has a positive and significant effect on purchasing decisions mediated by competitive advantage.(Rizki et al., (2024) There is also an indirect influence between e-service quality on Purchase Decisions with Brand Image variables as a mediating variable (Puspa:2019) and in the research on the role of brand image in mediating product quality on purchase decisions, it shows that brand image is able to mediate the influence of product quality on purchase decisions (Bagus, et al., (2019) Endorser credibility has a positive and significant effect on the purchase decision mediated by Brand Image The results of the processing of respondent data found that Endorser credibility had a positive and significant effect on the purchase decision.The higher/more positive the Endorser credibility will affect the purchase decision to be higher/more positive.In this study, Brand Image is a variable used to mediate the variables of Endorser credibility, and service quality And the results of the data processing that can be collected state that Brand Image has succeeded in becoming a variable that mediates Endorser credibility significantly.
Brand Image is able to increase the influence/mediate of Endorser credibility on purchase decisions.This means that the higher/more positive the mediation influence of the Brand Image , the more it will increase the Purchase decision (This is in line with previous research.The existence of Brand Image as a mediating factor can increase the influence of mediating Endorser credibility on Purchase decisions.In research conducted by (Resa et al., (2023) and in other research, Endorsement Credibility has a significant positive effect on purchase decisions mediated by brand image.Putri et al., (2023)

CONCLUSION
The study concludes that service quality and endorser credibility at SMK Jaya Buana significantly influence prospective students' purchase decisions, with an even stronger impact when mediated by brand image.Service quality is the largest contributor to purchase decisions, followed by endorser credibility.To maximize these effects, the school should enhance service standards and bolster the credibility of endorsers who can effectively influence potential students.Additionally, strengthening the brand image, particularly through improving school facilities and forging industry partnerships, further boosts purchase decisions.The findings confirm that service quality and endorser credibility both positively impact brand image and, in turn, significantly enhance purchase decisions when mediated by a strong brand image.

Figure 1
Complete SEM ModelSource: Data Processing Results (2024) CFA can be said to have two focus of study, namely; (1) whether the indicators conceptualized unidimensionally are valid, and (2) what dominant indicators form the constructed construct studied.The reference value of the loading factor estimate (Ghozali, 2016) should ideally be above 0.50.The results of the CFA test are shown in Table 4.7 which shows the loading factor values of each indicator and each dimension to the construction where all values are > 0.5 which means that the indicators and dimensions of this study are valid for measuring the construction.

Figure 2
Direct and Indirect Effects of SQ, EC, on PD (direct) through BI mediation (indirect)Source: Data Processing Results(2024) The Effect of Service Quality and Endorser Credibility on Purchase Decision Mediated By Brand Image (Empirical Study: Active Students of Jaya Buana Vocational High School in Tangerang Regency)

Table 1 CFA (Confirmatory Factor Analysis) Test Results Source
: Data Processing Results (2024) The purpose of the Confirmatory Factor Analysis (CFA) test is to confirm or test a model, which is a measurement model whose formulation is derived from theory.
The Effect of Service Quality and Endorser Credibility on Purchase Decision Mediated By Brand Image (Empirical Study: Active Students of Jaya Buana Vocational High School in Tangerang Regency)

Table 2 Results of Reliability Testing of Research Variables Source
: Data Processing Results (2024)

Table 5 ,
Brand Image has a positive effect on the Purchase Decision with a P-Value of 0.000 With an estimated weight of 0.636 and compared to other estimated weight values, it can be said that Brand Image and Purchase Decision have the most influential variable relationship.