The Effect of Principal Leadership and Internal Communication on Teacher Performance in Indonesia

This research aimed to 1) investigate the effect of principal leadership based on teacher perception on teacher performance, 2) investigate the effect of internal communication between principal and teacher on teacher performance, and 3) investigate the effect of principal leadership and internal communication on teacher performance. Causal comparative method was performed in this research. 110 teachers from private high schools in Indonesia were the population in this study. Questionnaires were used to collect data for all variables. T-test and multiple regressions were performed to analysis hypotheses in this study. Results indicated that principal leadership has a positive effect and significantly correlates with teacher performance. Also, internal communication between principal and teachers has a positive effect and significantly correlates with teacher performance. In addition, principal leadership based on teacher perception and internal communication has a positive effect on teacher performance. Therefore, it is essential to do further research about another factors influencing teacher performance.


Introduction
Teachers are professional educators who have the task of educating, teaching, guiding, directing, training, assessing, and evaluating students in formal education, basic education, and secondary education. Therefore, tasks that must be performed by teachers, making them as the center of attention improve the quality of education. The quality of education will be adequate if the teachers' performance is adequate.
However, the ability of teachers to improve their performance does not always develop properly. In addition, teachers' performance is still relatively poor. It is caused by an influence from other factors, such as within teacher's personality or outside the teacher's personality.
Mahgoub & Elyas stated that development of teacher performance was in the low level, because they had not been able to interact with students and their teaching methods were still using conventional ones [2]. Therefore, teachers must be encouraged with teaching aids that can assist in learning such as communication skills, discussion and dialogue, problem-solving, role-play, discovery, and brainstorming.
Research showed that vocational high school teachers had low pedagogic and professional performance. It was influenced by factors of expectations about reward, teachers' abilities, encouragement, internal and external rewards, and low job satisfaction. Besides, there were also found problems and constraints on teachers, 1) quality, quantity, and distribution, 2) welfare, 3) teacher management, 4) teacher appreciation, and 5) teacher education [3].
Findings showed teacher performance was low due to teacher expertise in elementary, junior high, high school and vocational high school levels in mastering material by 27.67% of the target. This percentage is still below the average of minimum of 75%. It means, 40% of middle and high school teachers taught outside their expertise. As a result, there are still many teachers who teach without preparation and are monotonous. According to Supardi [10], teacher performance is an effort made by teacher in teaching and learning activities to improve students' learning outcomes. In line teachers must possess four competencies, namely professional, personality, pedagogic, and social.
In this case, the expertise possessed by teachers to carry out their duties is assessed from the mastery of competencies, teachers' ability in teaching, and the application of knowledge. Assessment of the teachers' ability to carry out their responsibilities is called Teacher Performance Assessment. Teacher performance assessment is the assessment of each teacher's assignment in rank, position, and career guidance. Teacher performance assessment system aims to see 1) the level of teacher mastery, 2) the level of effectiveness and efficiency of teacher performance, 3) to provide a foundation for decision-making 4) to provide a foundation in the professional development program for teachers, 5) to guarantee teachers to carry out tasks and responsibilities, 6) to provide a system to improve teacher promotion and career path with other forms of appreciation [4]. Teacher performance assessment results vary due to several factors including work environment, individual teacher, and leadership. In the leadership factor, which is the principal leadership, as the principal must carry out the duties optimally and be able to lead the school in good direction and wisely, and the objectives can be achieved optimally to improve the quality of education in schools [5].
Nonetheless, the leadership of school principal depends on teacher because teachers are the pivotal elements in implementing education. Leadership is something that can influence other people to follow them as expected [6]. According to Syarifudin [7], principal leadership is the ability of a leader to persuade and convince subordinates that they are committed and enthusiastic to follow their leader. Moreover, there are misunderstandings and the unclear information obtained by teachers, which make it difficult for teachers to carry out the instructions given by the principal. The misunderstanding of these teachers is internal communication, so internal communication must be well-established. According to Ardana [8], internal communication is an exchange of information, both oral and written, or with communication tools within an organizational environment.
Based on the observations in private high school in Surakarta, Indonesia, the average of teacher performance level increased every year, but it was not significant. It was shown from the lack of encouragement from the school principal, the completion of less effective lesson plan. many students did not understand the explanation and had poor internal communication with their teachers. For these reasons, principals of this private high schools in Surakarta, Indonesia might have proper strategy to improve teacher performance, which is to carry out school principal leadership and internal communication.
The purpose of this study is to investigate: 1) the effect of principal leadership on teacher performance in private high school, 2) the effect internal communication on teacher performance, also, 3) the effect of principal leadership and internal communication on teacher performance in the private high school in Surakarta, Indonesia.

Materials and Methods
This is a causal comparative research using census design [9]. Population in this study is teachers in Muhammadiyah private high school which consisted of four schools, Muhammadiyah private high school number 1, Muhammadiyah private high school number 2, Muhammadiyah private high school number 6, and Special Program of Muhammadiyah private high school. By using saturation sampling, all of the population were used as respondents. It was 110 teachers for four schools. The population refers to opinion of [9], if part of the population is taken based on a certain amount, but if the population is close to 100 then all population can be taken as a sample.
The instruments in data collection consist of questionnaire and the preparation of previous questionnaires that had been tested on 20 teachers. The trial of the instruments was outside the scope of the Muhammadiyah Senior High School in Surakarta, Indonesia. The trial is used to test the validity and reliability of the data [10]. Data collection techniques used are questionnaire [11] and documentation [12]. The dependent variable of this study is teacher performance (Y), while the independent variables are the principal leadership (X1) and internal communication (X2). As for the data presentation techniques in this study used tables [9]. Data analysis techniques used with data prerequisites are normality test, multicollinearity test [13], and linearity test, multiple regression analysis [14]. To test hypotheses, t-test and F-test performed [15], also determinant coefficient (R 2 ), effective contribution and relative contribution.

Results and Discussions
The result of the first prerequisite analysis is the normality test. The normality test aims to see whether the research sample data was normally distributed or not. In Test was carried out using SPSS, then the three variables obtained significance > 0.05, which means all variables were normally distributed.
The result of the second prerequisite analysis is the multicollinearity test. The purpose of this test is to see whether the regression model shows the correlation between the independent variables. A good regression model does not show correlation on the independent variable. To find out the occurrence of multicollinearity or not with a tolerance number> 0.1 and VIF <10, it is concluded that there was no multicollinearity. The table is presented as below.  The linearity test results above indicate that p> 0.05, which implies that the regression model of each variable has a linear or straight-line relationship.
The next test after the prerequisite tests have been met is multiple analysis. The analysis was carried out to find whether or not there was a joint influence of principal leadership and internal communication on teacher performance. Furthermore, testing the hypothesis through a partial test (t-test) and simultaneous test (F test). t-test was carried out to find the significant effect between the independent variable of the principal leadership and internal communication on the dependent variable, which is teacher performance. Then the hypothesis can be accepted or rejected.
T test results on the principal leadership variable (X1) can be seen t > t table (6.080 > 1.982) then Ho is rejected. Thus, there was a positive influence on the principal leadership on teacher performance, and therefore the first hypothesis is accepted. T-test results on the internal communication variable (X2) can be seen t > t table (2.925 > 1.982), then Ho is rejected. Hence, there was a positive effect of internal communication on teacher performance, and therefore the second hypothesis is accepted.
The F-test was used to find the influence of the principal leadership and internal communication simultaneously on teacher performance. F-test results can be seen F > F table (31.222 > 3.08), meaning Ho is rejected. So, there was a significant influence on the principal leadership and internal communication on teacher performance, which implies the hypothesis assumed is accepted. Then, the principal leadership and internal communication affected the performance of Private high school teachers in Surakarta, Indonesia.
The coefficient of determination (R 2 ) proves that the variation of the dependent variable can be shown as the independent variable in the model. The results of R 2 are from 0 to 1. If R 2 is close to 1, then it proves that the dependent variable can simultaneously be shown an independent variable. Likewise, if the number R 2 is near to 0, it means that the dependent variable cannot be shown as an independent variable. The results show the coefficient of determination (R 2 ) of 0.369. The value of R 2 on the principal leadership and internal communication variables influences the teacher's performance by 36.9%, while the remaining 63.1% was influenced by other variables not examined.
The results of the research analysis show that the principal leadership and internal communication were jointly positive for the performance of Private high school teachers in Surakarta, Indonesia. This can be seen from the linear regression equation as follows Y = 73.803 + 0.707 X1 + 0.314 X2. Based on this equation, it is known that the regression coefficient on each independent variable was positive, meaning that the principal leadership and internal communication variables together have a positive effect on the performance of Private high school teachers in Surakarta, Indonesia.
The first hypothesis test results determine that the regression direction coefficient of the principal leadership variable (X1) was 0.707 or positive, it explains that there was a positive influence of the principal leadership on teacher performance. Then, the significance test of the multiple linear regression coefficient for the principal leadership variable (X1) obtained t > t table, which was 7.028 > 1.982 and a significance value < 0.05, namely 0.000 with a relative contribution of 83% and an effective contribution of 30.6%. It concludes that the better the principal leadership, the higher the teacher performance.
Conversely, the lower the principal leadership, the lower the teacher performance. This is supported by theoretical studies and relevant researches. Principal leadership is a skill possessed by the leader as well as ownership of qualifications, positions, and appointments by the educational unit authorized to influence members to act following educational objectives [16]. In line with, there was a positive and significant influence of principal leadership on teacher performance [17]. Besides, Firmawati, Yusrizal, & Usman state that there was a significant influence between the principal leadership on the teacher's performance by 35.8% [18].
The second hypothesis shows the regression coefficient of the internal communication variable (X2) of 0.314 or a positive value, so there was a positive influence of internal communication on teacher performance. Based on the t-test for internal communication variable (X2), it obtained t > t table, which was 2.925 > 1.982 and a significance value < 0.05, namely 0.007 with a relative contribution of 17% and an effective contribution of 6.3%. It concludes that that the better the internal communication, the higher the teacher performance, otherwise, the lower the internal communication, the lower the teacher performance.
The results of the study are consistent with the theories and relevant researches. According to Ardana [8], internal communication is the delivery or information exchange from the sender to the recipient, in written, oral, or use a communication tools in the organizational environment. This is in line with the results of research conducted by Jonathan [19] which state that there was a positive significant relationship between the communication of principals on teacher performance in secondary schools (r = 0.603; p > 0.05). In line with, Wibowo said that there was a positive and significant effect of internal communication on teacher performance (R 2 = 0.081) [20].
The third hypothesis test on the significance test of multiple linear regression or F test found that the value of F > F table was 31.222 > 3.08 and the significance value < 0.05, which was 0.000. It means the principal leadership and internal communication together have a positive effect on teacher performance. Based on the conclusion, it can be seen that the tendency of increasing in the combination of principal leadership and internal communication will be followed by an increase in teacher performance, whereas the tendency for a decrease in the combination of the principal leadership and internal communication variables will be followed by a decrease in teacher performance.
The third hypothesis is in line with the relevant theory. Teacher performance is a performance implemented by teachers to carry out their duties as educators [21]. This is following Supriadi & Mutrofin [22] explained that the principal communication and leadership quality significantly affected teacher job satisfaction, with the regression equation of Y = 13.90 + 0.30 X1 + 0.47 X2 + e.
The coefficient of determination was obtained as much as 0.369, which is the effect on the combination of principal leadership and internal communication variables on the teacher performance of Private high school in Surakarta, Indonesia by 36.9%, while the rest was influenced by other variables.
The calculation results of the principal leadership variable contained a relative contribution of 83% and an effective contribution of 30.6%. The internal communication variable contained a relative contribution of 17% and an effective contribution of 6.3%. There was a comparison of the number of relative and effective contributions that the principal leadership variable had a dominant influence on teacher performance of Private high school in Surakarta, Indonesia compared to the internal communication variable.

Conclusions
Based on the purpose of the study, the examination of the hypothesis on the problems raised can be obtained as follows. The t-test result on the principal leadership variable t count was 6.080, while the t-table was 1.982 so that the principal leadership had a significant influence on teacher performance with a significance of 0.05, which was 0.000 with an effective contribution of 30.6% and a relative contribution of 83%. it proves that there was an influence of principal leadership on the teacher performance of Private high school in Surakarta, Indonesia.
T-test result on the internal communication variable count was 2.925, while the table was 1.982, so internal communication had a significant influence on teacher performance with a significance of 0.05, namely 0,000 with an effective contribution of 6.3% and a relative contribution of 17%. It proves the influence of internal communication on the teacher performance of Private high schools in Surakarta, Indonesia The results of the analysis of the F-test on F = 31,228 > F table = 3.08, mean that Ho is rejected, so that simultaneously there was a significant influence of principal leadership (X1) and internal communication (X2) on teacher performance (Y). These results prove that there was a significant influence of principal leadership and internal communication on the teacher performance of Private high schools in Surakarta, Indonesia. In this case, the hypothesis tested. The results of R 2 or the coefficient of determination obtained R 2 = 0.369, which means 36.9% of the principal leadership and internal communication affected teacher performance, while the remaining 63.1% was influenced by other variables that were not examined.