Human resource management in improving students’ academic achievement mediated by teacher’s performance

The role of teacher is critical in improving students’ academic performance. Teacher’s performance is affected by many factors. This study analyzes and examines the effect of organizational culture, leadership style, work ethic, and work commitment on teacher’s performance and students’ academic achievement. The study applies the analytical research involving private high school teachers in the district of Jember East Java Province of Indonesia. There are 313 private high schools in Jember with more than 5,000 teachers. The sample consists of 213 respondents. The main research data were obtained by distributing the questionnaires. It uses path analysis to determine the direct and indirect effect using the structural equation modeling. The results show that organizational culture, leadership style, work ethic, and work commitment have a significant positive effect both on teacher’s performance and students’ academic performance. Besides, teacher’s performance plays a significant mediating role in the relationship between the independent variables and students’ academic performance. Arief Tukiman Hendrawijaya (Indonesia)


INTRODUCTION
Human resources management plays a significant role in making an organization successful. This is because human resources are the main determinants for improving the output of the organization. Thus, having good strategies for human resources development is essential. In terms of organizational strategy, having a sustainable competitive advantage will drive the success of an organization. The public service sector has been considered a bureaucracy, politically influenced, and unprofessional (Ahmad & Halimah, 2017). Nowadays, an organization always deals with dynamic and constantly changing conditions, so the organization is required to look for approaches with the ultimate goals to be achieved specifically to take a strong position to win a competition. By gaining an advantage, human resources will be encouraged to get a position that is a major component, more than any organization can see (Allameh, Barzoki, Ghazinour, Khodaei, & Abolghasemian, 2014).
The contribution of human resources to an organization is significant since they are very valuable and serve as the backbone of the organization. Employees or teachers are the main resources that might be strategically positioned for the organization to achieve excellence. It was emphasized that special and valuable resources could create an advantage. Studies show that organizations can improve and maintain excellence through the management of specialized human resources (Khan, 2010). Therefore, this study was conducted to examine the effect of human resource management practices on employees' performance in the public sector.
Serious efforts for improvement of the quality of human resources in Indonesia must be continuously made in line with the progress of science and technology. Improving the quality of Indonesia's human resources is essential because human resources are one of the basic national assets and determinants in national development in Indonesia. According to Dessler (2010), human resource management strategy is any effort to connect human resources management with strategic roles and goals in order to enhance business performance and develop organizational culture and to encourage innovation along with flexibility, so it seems that organizational leaders must link the application of human resources management with strategy organization to improve performance and develop an organizational culture that will support the application of innovation and flexibility.
The fulcrum in human resources as valuable guidance in an organization reflects more pressure on intangible resources than the real ones. Becker, Huselid, and Ulrich (2001) point out that investment in human resources aims to benefit the organization in the short and long term. Employees will be motivated to continue to learn to build a superior business environment if they are given a chance to improve their skills and abilities. Human resources must have been a key driver of other resources and organization must have a strategic position that helps to realize the performance of corporate organizations with competitive advantages (Wright, Gardner, Moynihan, & Allen, 2005).
Previous studies have been directed to test the relationship between organizational commitment, leadership style, and performance of employees. For example, Avolio, Zhu, and Bhatia (2004) report a positive association between organizational commitment and servant leadership, and between employee performance and outcome. Schneider and George (2010) show a positive relationship between effective leadership style and employee outcome, which is mediated by employee empowerment in voluntary service organizations.
Issues regarding human resource management, which includes organizational culture, leadership style, work ethic, and organizational commitment concerning teacher's performance in improving students' academic achievement, are interesting matters to study. Therefore, based on these descriptions, it is interesting to study and analyze the effect of organizational culture, the style of leadership, work ethic, and work commitment on students' academic performance. Besides, it is also stimulating to examine the mediating role of teacher's performance on the relationship between organizational culture, the style of leadership, work ethic, work commitment, and students' academic performance.
The study was performed in the district in Jember of East Java Province of Indonesia. Jember has a population of more than 2.8 million. It has more than 300 private senior high schools. Most of the previous studies in the Jember district used the public schools, which, to some extent, have the advantages as fully-government supported institutions (Priyono, Qomariah, & Winahyu, 2018;Syaidah, Suyadi, & Ani, 2018). Examination on the private institutions would give some ideas on the aspects related to teacher's performance and students' academic performance. Besides, a study by Hendrawati and Prasojo (2015) shows that transformational leadership, school culture, and teacher's motivation directly and positively affect students' achievement.
This study examines a sample of 213 private high school teachers and finds that organizational culture, leadership style, work ethic, and work commitment positively and significantly affect both teacher's performance and students' academic performance. The study also reports that teacher's performance plays a significant mediating role.

LITERATURE REVIEW AND DEVELOPMENT OF HYPOTHESES
Discussion on human resources management is closely related to organizational culture. Culture is an outlook toward life commonly recognized as a way of thinking, behavior, attitude, and value reflected both in physical and non-physical forms. According to Schein (1992), culture is a rule, values, principles, and basic assumptions that can direct an organization. Furthermore, he states that culture is formed from three elements that form the basic understanding of organizational culture, namely artifacts, values adhered to, and basic assumptions underlying them.
In addition to organizational culture, leadership style is also something that can be associated with human resources management. Leadership style is a pattern of action that is adapted to the situations and conditions and students' maturity. Through leadership style, it is expected that students with different levels of maturity will behave appropriately according to their maturity and will eventually be able to follow and master the materials taught by the teacher. The teacher's leadership style will determine the results of learning. Blanchard and Hersey (2011) suggest that leadership is the process by which a person influences individual and group activities to achieve goals in a certain situation.
Leadership style will determine the extent of leadership effectiveness. This is because a leader with a good leadership style would be able to accomplish the goals of any organization. A leader must be able to direct and move the people that he leads to follow his abilities depending on his leadership style. Previous studies have been carried out on very well-known leadership styles, such as the transformational leadership style (Dvir, Eden, Avolio, & Shamir, 2002). Previous studies have shown is a positive relationship between employee performance and leadership style (Whetsone, 2002; Ehrhart, 2004). Arrowsmith and Alastria (2004) conclude that effective and efficient conduction of old-fashioned school thoughts and management might work within organizations of service sector, volunteers, charities, and other non-profit organizations and non-governmental organizations.
Work ethic and organizational commitment are other forms related to human resources management. Work ethic comes from the word "ethikos" derived from the Greek word of "ethos." It means a custom or character, while "work" means the activity of doing something. Hence, work ethic means attitudes, personality, character, and belief in something. Cultivation of a work ethic needs to be performed from the beginning so that employees will get used to carrying out tasks and work with a full sense of responsibility. Work ethic is closely related to one's performance. People who have a high work ethic will have better performance. People who have a high work ethic will not easily give up in facing work problems as they have high motivation and creative and innovative spirit.
Generally, organizational commitment could be defined as an employee bound to the organization at work. In this respect, commitment is demanded by the organization. As a result, competent human resources could be well conserved and maintained.
Organizational commitment usually is meant as a measure of employee strength related to organizational goals and values (McNesee-Smith, 1996). Thus, organizational commitment is a value orientation concerning the organization, which shows that the individual thinks about and prioritizes his work and organization. Commitment means the focus and need for individual attachment to a particular task or job (Abdullah & Ismail, 2012). Employees' organizational commitment will go up if they work in a good work environment. Organization having strongly committed employees is associated with lower employee turnover rate. To achieve stability and maintain competitive position, it is essential to increase the level of employee commitment. An attractive work environment is perceived to be able to bring about employees to be more committed, increases motivation, and the level of satisfaction. Organizational commitment is influenced by the dissimilar number of outcomes (Danish, Ramzan, & Farid, 2013). These could include work environment, changeover, motivation, and organizational support.

Determinants of teacher's performance
Organizational culture contains shared values, beliefs, and assumptions about how members should act (Lussier, 1997 (2002) argue that it is not a single unitary concept, but rather a collection of attitudes and beliefs regarding work behavior. Furthermore, Petty (1995) points out that the work ethic as a trait that must be possessed by workers to be able to produce maximum work, which consists of some aspects. First, interpersonal skills that describe work relationships with others. This aspect includes personal traits that advocate good interpersonal relationships and make a positive contribution to performance in the context of cooperation. Second, the initiative shows the traits which advocate raise to a job and give the impression of dissatisfaction with performance that is in a fixed, reliable state. Third, it is reliable in explaining the quality that touches the expectation fulfilment for satisfaction of performance and full approval inherent in a work assignment (Petty & Hill, 2005).
Organizational commitment is one of the behaviors in the organization that plays a significant role in the organizational development. A teacher's commitment to an organization (school) largely determines the loyalty and level of teacher's engagement in efforts to advance the organization. Teachers are educators who carry out services in guiding students. The guidance is in the purpose of helping students achieve life goals that include social-personal, learning and career aspects so that they can carry out their role as teachers and educators that should build commitment to their work. Every school must have a strategy to bring up teacher's performance. The strategy must deal with efforts of how to build, improve, and maintain high commitment. It also can continually develop individual competencies with strategies to create learning organizations in such a way that will then improve teacher's performance.
The hypotheses proposed based on the above descriptions are as follows:  (2009) advocate that a teacher should focus not only directly on teaching and learning but also on the importance of improving students' achievement. As leaders, teachers shall also look and integrate the curriculum and assessment, and the development of enhanced teaching programs.
Organizational commitment is defined as a nous of identification, involvement, and loyalty (Morris & Steers, 1980). It is a condition where members are dealt with and interested in the organization's goals and values. It also means more than just formal membership. It includes an assertiveness of organizational commitment and alacrity to strive for the best possible effort to attain the goals of the organization. In short, organizational commitment consists of many elements. These are organization loyalty, work involvement, and organizational identification on values and goals. In other words, organizational commitment is the level of trust in the acceptance of organizational goals by members and has a desire to remain in the organization (Mathis, Jackson, Valentine, & Meglich, 2016).
Teacher's performance reflects the teacher's workability seen from the teacher's work performance in carrying out his duties as a teacher. If the workability of a teacher is good, the performance will also be higher. Conversely, if the workability of a teacher is not good, then the performance will also be lower. Teacher's performance in a school has a significant part in attaining school goals. The issues of teacher's performance have been under the spotlight of various parties that should receive central attention. This is because the figure of a teacher is the main focus when talking about educational problems. The teacher is always associated with any component in the education system. The teacher plays a major role in the development of education, especially those that are held formally in the school. Besides, the teacher determines the success of students, as indicated by students' academic achievement.
The hypotheses proposed based on the above descriptions are as follows:

Mediating effect of teacher's performance
Organizational culture can be used as a guide for how members of the organization should behave, what is acceptable and unacceptable, and recommended behavior in work so that organizational goals can be attained efficiently and effectively.
There is an association between organizational culture and the existing climate of the school, which is an atmosphere of work, learning, communication, and getting along within educational organizations.
With the establishment of conducive school culture, the teacher will feel comfortable when working and be motivated to work better and greatly support the improvement of teacher's performance. An increase in teacher's performance will make students get higher grades or academic achievements.
Effective and efficient leadership style in classroom learning requires teachers to improve their performance in order they can pay attention and provide different treatment according to students' maturity. If teachers have been able to apply or adjust the leadership style in learning optimally by taking into account the level of students' maturity, then they can be called good teachers because it can make learning effective and efficient. As a result, the specified goals can be achieved. Teachers must be able to identify the students' maturity, so they can identify which level of ability students belong to (low, me-dium, and high classes). Teachers can apply leadership styles under the ongoing situation in classroom learning so that learning can run effectively and efficiently. Therefore, students can achieve high performance or improve their achievement.
A high work ethic of a teacher contains the absolute requirements of a teacher in providing learning on the subjects taught, and this shows the teacher's high performance, while students will make stimulants to always be obsessed with doing their best. Therefore, the teacher must always improve his work ethic through learning and lessons from his teaching experience. The more he knows, the more he can give to students.
The teacher's commitment is a form of obedience to the rules, rules of the game, and obligations related to their work. Teacher's performance requires work standards; in this case, the rules that exist as guidelines for teachers in carrying out their duties. Thus, the teacher who has high commitment will be able to improve his performance, and the impact will be seen on students' academic achievement.
The hypotheses proposed based on the above descriptions are as follows:  Seivers (2007). Students' academic achievement was obtained from the average value of learning outcomes of classes taught by the respondents. Data analysis used path analysis assisted by the AMOS program to know the direct and indirect effects of exogenous variables (organizational culture, leadership style, work ethic, work commitment) on endogenous variables (teacher's performance and students' academic achievement). According to Baron and Kenny (1986), path analysis is used because of its superiority to test direct and indirect effects with mediating variables (teacher's performance).

Respondents data
The number of samples was 213 respondents who were private high school teachers in Jember city. Respondent characteristics data included gender, classes taught, age, and latest education. Each of these characteristics is presented in Table 1.
The general description of respondents shows that the majority of research respondents are female (65.3%), teachers of grade XI (37.6%), aged below 31 years (26.8), and hold their latest educational degree or diploma (49.3%).

Path analysis
The results of testing the direct effect of the variables of organizational culture, leadership style, work ethic, work commitment on teacher's performance, and the variables of organizational culture, leadership style, work ethic, work commitment, and teacher's performance on students' academic achievement are presented in Table 2.
Based on Table 2, the direct effect on all variables has a positive coefficient, which means any increase in exogenous variables (organizational culture, leadership style, work ethic, and work commitment) will be followed by an increase in endogenous variables (teacher's performance and students' academic achievement).
The results of statistical tests of the mediating (indirect) effect of teacher's performance on organizational culture, leadership style, work ethic, and work commitment on students' academic achievement are presented in Table 3.   The results of hypothesis testing on the path of indirect effect show that all indirect paths have a very significant effect, which means that teacher's performance can mediate the effect of organizational culture, leadership style, work ethic, and work commitment on students' academic achievement. Table 4 shows the recapitulation of the test results, presents the direct effect, indirect effect, and total effect of exogenous variables on the endogenous variables (teacher's performance and students' academic achievement). The exogenous variables are organizational culture, leadership style, work ethic, and work commitment.
Based on the table, each total effect of the independent variable is organizational culture by 16.7%, leadership style by 14.1%, work ethic by 19.2%, and work commitment by 17.0%. In general, the results of path analysis test are shown in Figure 2.

DISCUSSION
The study finds out that organizational culture affects teacher's performance positively and signifi-cantly. As has been argued, organizational culture is an invisible social force that can move people in an organization to perform work activities. With good organizational culture, teachers will be responsible for their work and can be completed effectively and efficiently. A good organizational culture reflects the level of one's sense of responsibility for the tasks assigned to him. This encourages the improvement of teacher's performance. This research supports Triwahyuni, Abdullah, and Sunaryo (2014) who found a positive and significant effect of organizational culture on teacher's performance.
Leadership style affects teacher's performance positively and significantly. Teachers play a very important role in the management of schools. Leadership style is a very prominent aspect in carrying out classroom management tasks because with leadership style, the teacher's performance will run well. This study also supports Triwahyuni et al. The study reports a positive and significant effect of work ethic on teacher's performance. A teacher who has a high work ethic will tend to have higher performance. If related to the situation of developing human life, a high work ethic will be used as an absolute requirement, which is grown in life. This will open views and attitudes to people to highly evaluate hard and serious work so that it can erode the work attitude that is not serious. According to Turk and Vignjević (2016), the mechanisms and methods for the improvement of work ethic can and must be clearly meant and recognized. Apart from uttering work ethics guidelines in the documents mentioned above, promoting work ethics in each teaching situation is important. This is carried out to guarantee a better future for education for all students. Thus, raising awareness and educating teachers about the importance of work ethics and the acquisition of related skills is very crucial.
Work commitment has a positive and significant effect on teacher's performance. Teachers who carry out the learning process within an exciting atmosphere tend to be more productive. Based on overall productivity and satisfaction data, teachers who are more satisfied tend to be more effective than those who are less satisfied. What is meant by effective is that the teacher can achieve his goals when he is working, namely achieving certain productivity set by the organization where he works (Robbins & Judge, 2007), thereby increasing its performance.
Organizational culture affects students' academic achievement positively and significantly. Studying organizational culture is more focused on things that cannot be observed, especially values as the core of culture. More meaningfully, values are the basis for understanding, attitude, and motivation, as well as a reference for a person or group in choosing a goal or action (Olasanmi, 2016). This aspect of value is then manifested in the tangible cultural forms that can be observed both physically and behaviorally. Thus, the physical condition and behavior of school residents are based on assumptions, values, and beliefs.
Leadership style affect positively and significantly students' academic achievement. The teacher is the most important component in students' achievement since he is always with students every day in the learning process. The teacher, as a leader, must have a leadership style that is adjusted to the lev-el of students' maturity. Students are unique creatures. They have different characteristics from the others. Therefore, teachers must treat students differently according to their level of maturity. The leadership style adopted is adapted to the existing situation and conditions.
Students' academic achievement is also affected by work ethic. A high work ethic in a good learning atmosphere naturally leads to the achievement of good students' learning outcomes. As the vanguard in the implementation of the learning process, the teacher is in the spotlight of the community related to the work ethic, namely the totality of dedication and loyalty. This highlight boils down to the teacher's inability in the learning process that impacts on the declining quality of education. Even if the spotlight leads to teacher's weaknesses, it is not entirely a burden because there might be an affecting system. Teacher's work ethic will have an impact on quality education.
The effect of work commitment on academic achievement is positive and significant. Royle (2012) states that the need for achievement is a power in the human mind to perform an activity. People who have high achievement need experience satisfaction not because they get rewards from their work, but rather because their work is considered good. There is an inner satisfaction when he completes his work perfectly. Thus, teachers having good work commitment will make better, faster, more effective and efficient efforts.
Teacher's performance has a positive and significant effect on students' academic achievement. Teacher's performance is measured in during classroom learning activities, which are assessed by students including open lessons, explaining the subject matter, teacher's ability in mastering teaching material, mastering learning methods, teacher's skills in using media, students' questioning skills, teacher's behavior during learning, teacher's assessment of learning and closed lessons. These results support Altun (2017) who found that teacher's commitment is an important factor influencing students' achievement.
Organizational culture affects students' academic achievement, and the effect is mediated by teacher's performance. This shows that teacher's performance can mediate the effect of organizational culture on students' academic achievement.
Organizational culture can be used as a guide for how members of the organization should behave, what is acceptable and unacceptable, and recommended behavior in working so that the organizational goals can be achieved efficiently and effectively. Indeed, there is an association between organizational culture and the existing climate of the school, which is an atmosphere of work, learning, communication, and getting along within educational institutions. With the establishment of conducive school culture, the teacher will feel comfortable when working and be motivated to work better and will greatly support the improvement of teacher's performance. Increasing teacher's performance will result in students' higher grades or academic achievement.
Leadership style affects students' academic achievement. This effect is mediated by teacher's performance. This shows that teacher's performance can in mediate the effect of leadership style on students' academic achievement. Effective and efficient leadership style in classroom learning requires teachers to improve their performance so that they can pay attention and provide different treatment according to students' maturity. Teachers must be able to identify the students' maturity, so they will know which class students' ability belongs to (low, medium, and high). Teachers can apply leadership styles under the ongoing situation in classroom learning so that learning can run effectively and efficiently to enable students to achieve high performance or improve their achievement.
Teacher's performance mediates the effect of work ethic on students' academic achievement. This shows that teacher's performance can mediate the effect of work ethic on students' academic achievement. A high work ethic of a teacher contains the absolute requirements of a teacher in providing learning on the subjects taught, and this shows the high teacher's performance, while students will make stimulants to always be obsessed with doing their best. Therefore, the teacher must always improve his work ethic through learning and taking lessons from his teaching experience. The more he knows, the more he can give students.
Work commitment affects students' academic achievement and the relationship is mediated by teacher's performance. This shows that teacher's performance can mediate the effect of work commitment on students' academic achievement. Teacher's commitment is a form of obedience to the rules, rules of the game, and obligations related to their work. Teacher's performance requires work standards, in this case, the rules that exist as guidelines for teachers in carrying out their duties, so that a teacher who has a high commitment means that they can improve their performance and the impact will be seen on students' academic achievement.

CONCLUSION
This study was conducted on 213 private high school teachers in Jember city to study and analyze the factors directly or indirectly affecting students' academic performance. The results show that the variables of organizational culture, leadership style, work ethic, and work commitment has a positive and significant direct effect on teacher's performance and students' academic achievement. The teacher's performance is indirectly able to mediate the effect of the variables of organizational culture, leadership style, work ethic, and work commitment on students' academic achievement in Jember city. Overall the study accepts the proposed hypotheses. All independent variables have positive and significant effect on teachers' performance and students' academic performance.
The limitation in this study is that this study was carried out only on high school teachers, not including public high school teachers or elementary or junior high school teachers, so they have not been specialized in one aspect. Future research can be carried out by exploring broader research variables such as learning methods, etc. Besides, research can also be conducted on lecturers who are specialized in higher education in Jember city.