The Effect of Self-Confidence on Students' Understanding of Mathematical Concepts through the Implementation of the Independent Curriculum

Abstract


INTRODUCTION
Planned education in terms of quality and quantity can realize optimal education implementation to achieve learning goals (Andriani & Indrayany, 2020). Indonesia's education quality is still far behind, coupled with the competencies possessed by students deemed incapable enough to compete with other countries. This was reinforced by Isroila et al., (2018) who explained the results of a survey conducted by PISA that the ranking of educational competency scores in Indonesia had decreased in 2015 and made Indonesian education below the world average. One of the assessment methods that can be used to measure the competence of Indonesian students at the global level is PISA (Program for International Student Assessment). According to the results of a survey conducted by PISA, the assessment of Indonesian students is at level 74 out of 79 countries.
There are several factors experienced by students in studying, one of the factors that are often experienced by students is a feeling of boredom when teaching and learning activities are taking place at school. This is sometimes caused by the teacher-centered learning method which is often used by educators who are considered unsatisfactory and unpleasant for students so that students feel sleepy and bored (Isroila et al., 2018). Another factor that causes student boredom when in class is the material being taught is not understood by students. Some of these things can affect the increase in student achievement. In 2019 the government through the Ministry of Education and Culture carried out a massive revolution by overhauling the world education curriculum, this revolution began with the creation of the Freedom to Learn program which was implemented from elementary, secondary, to higher education levels.
Through the independent learning program, students are invited to be independent in learning. Freedom of learning means that students are given the freedom to explore anything with a sense of comfort and provide happiness in gaining knowledge without any pressure from anywhere so that students can develop their natural interests and talents from the start and increase their potential and hobbies, without forcing them to study. or mastering a field outside of the hobbies and desires of students. They also agree that independent learning is providing learning opportunities to learn according to their wishes without any pressure (Vhalery et al., 2022). Freedom of learning can also be interpreted as freedom of thought and includes actions that are reprehensible in common sense when students are given a burden beyond their abilities. This independent learning is a breath of fresh air in the world of Indonesian education, this program strives to be able to create a free learning environment without any psychological pressure.
Mathematics is one of the occupations that occupies an important role in the world of education. Rosmawati & Sritresna, (2021) explained that mathematics is a subject that can support the development of science and technology. The same thing was conveyed by Wulandari et al., (2016) who stated that Mathematics plays an important role in the development of science and technology. Learning activities in mathematics arganrain human abilities in logical, critical, creative, analytical, and systematic thinking, therefore mathematics is very important to learn from an early age (Handayani, 2015). Conceptual understanding is an important ability in building higher-order thinking skills (Kase et al., 2022).
Conceptual understanding is the ability to fully and functionally understand mathematical concepts (Lestari & Yudhanegara, 2017). Indicators of understanding the concepts that are a problem for students are (1) restating the concepts that have been learned; (2) grouping objects based on mathematical concepts; (3) applying the concept algorithmically; (4) mentioning examples or counter-examples of the concepts that have been studied; (5) presenting concepts in various forms; and (6) linking various mathematical concepts internally or externally (Lestari & Yudhanegara, 2017).
Based on observations made on mathematics learning at Wahidiyah Kediri Junior High School, the level of understanding of students' mathematical concepts in learning mathematics is still relatively low. This is shown when students answer the questions given, it can be seen that students are not able to solve the questions given properly. Students cannot restate a concept that has been learned and students have not been able to present the concept in various forms of mathematical representation. This is shown from the results of one student's answer in figure 1 below:

Figure 1. Student Answers Calculate the Perimeter and Area of the Trapezoid
Based on these answers it can be seen that the understanding of the concept of trapezium area is still low. Students cannot represent the trapezoidal area formula properly. As a result, calculating the area requires the number of parallel sides, but students choose to add up all of them, so students are not able to solve the problem properly. This was also confirmed by the results of an interview with one of the mathematics teachers, namely Mrs. SSR, who has taught mathematics for six years. He said that the level of students' understanding of concepts was still low, and students had difficulty solving questions if the questions were different from the examples given by the teacher. In addition, students are not active in class learning and lack guidance in working on math problems, so they are reluctant to take questions seriously. They start not being confident in their ability to do so they are lazy to try. When they don't know how to solve a problem, they tend to do it at random. When studying they are reluctant to ask the teacher or their friends about material that they do not understand. This shows that students have poor self-confidence, even though self-confidence is also very important for students.
Self-confidence is a feeling of belief and one's attitude towards the abilities one has and accepts sincerely both positively and negatively which are formed and learned through the learning process (Ameliah & Munawaroh, 2016). In addition, Lestari & Yudhanegara, (2017) states that self-confidence is an attitude of confidence in one's abilities and seeing oneself as a whole person concerning self-principles. According to Nurkholifah et al., (2018), several aspects used to measure self-confidence include; (a) Belief in one's abilities; (b) Being Optimist; (c) Being Objective; (d) Being responsible; (e) Rational and Realistic.
Self-confidence influences student achievement because those who have good self-confidence will always want and fight for achievement so that they will be successful in learning (Fitriani, 2015). In addition, the results of Ningrum & Sutrisno's research (2017) show that self-confidence has influenced mathematical reasoning abilities. So researchers are interested in knowing the effect of self-confidence on students' understanding of mathematical concepts through the implementation of an independent curriculum.

METHOD
This research uses a quantitative approach with the type of ex-post facto research design. Ex post facto is a study conducted to examine events that have occurred and then trace back to find out the factors that could have caused these events (Sugiyono, 2017). The population in this study were all students at Wahidiyah Kediri Junior High School, consisting of 447 students. The sampling technique in this study used a purposive sampling technique. The purposive sampling technique is a technique for determining research samples with certain considerations or criteria because this technique is more suitable for research that does not make generalizations (Arikunto, 2014). The criteria in question are students who are taught using the independent curriculum, because not all classes at Wahidiyah Kediri Junior High School apply the independent curriculum only in class VII as many as 3 classes, so a sample of 96 students is obtained.
Data collection in this study used questionnaires and tests. Where the questionnaire is used to determine students' self-confidence and tests are used to determine students' understanding of mathematical concepts. From the data from the selfconfidence questionnaire and understanding of mathematical concepts, they are categorized into three, namely high, medium, and low as below (Islami & Rusliah, 2019): Data analysis used in this study used simple linear regression whose calculations were assisted by the SPSS v.25 application for windows. So that the regression model is biassed, it is necessary to test the classical assumptions first (Ghozali, 2013). The assumption test in question is the normality z test, z autocorrelation test, and heteroscedasticity test.

Description of Self-Confidence and Understanding of Student Mathematical Concepts
Based on the results of distributing self-confidence questionnaires to students in class VII, an average of 38.4 was obtained with a standard deviation value of 10.21, a minimum score of 17, and a maximum of 59. The level of self-confidence of students in class VII at Wahidiyah Kediri Junior High School can be shown in table 2. below this: High 10 10,4% From table 2 it can be seen that 17.7% of the total respondents had a low level of self-confidence, 71.9% of the total respondents had a moderate level of self-confidence and 10.4% of the total respondents had a high level of self-confidence. Thus it can be concluded that most students of Wahidiyah Kediri Junior High School, especially class VII, have a moderate level of self-confidence.
Based on the test results for students' understanding of mathematical concepts in class VII, an average of 67.11 was obtained with a standard deviation value of 12.71, a minimum score of 33, and a maximum of 92. The level of understanding of mathematical concepts in class VII at Junior High School Wahidiyah Kediri can be shown in table 3 below this: High 5 5,2% From table 3 it can be seen that 15.6% of the total respondents had a low level of understanding of mathematical concepts, 79.2% of the total respondents had a moderate level of understanding of mathematical concepts and 5.2% of the total respondents had a high level of understanding of mathematical concepts. Thus it can be concluded that most students of Junior High School Wahidiyah Kediri, especially class VII have a moderate level of understanding of mathematical concepts.

Classical Assumptions
Testing the classical assumptions is carried out so that the regression model given is not biased so that the resulting regression model minimizes forecasting errors (Santoso, 2019). The following are the results of the classical assumption test performed  From table 5 it can be seen that the calculated DW value is greater than (du) = 1.688 which shows 1.646 < 1.728 < 2.354 so the regression model is free from autocorrelation problems. This means that there is a correlation between the interference error in period t and the interference error in period t-1 The last classic assumption test is the heteroscedasticity test. The heteroscedasticity test aims to test whether, in the regression model, there is an inequality of variance from one residual observation to another. A good regression model has homoscedasticity or does not have heteroscedasticity (Ghozali, 2013). The results of the heteroscedasticity test using the scatterplot graph are shown in Figure 1.

Figure 2. Scatterplots Graphic
Based on figure 2 which is shown by the scatter plot graph, it can be seen that the points spread randomly and are spread both above and below the number 0 on the Y axis. This shows that this regression model does not have heteroscedasticity.

Hypothesis Testing
After knowing the results of the thekalasi assumption test are fulfilled, then do the hypothesis test with simple linear regression analysis. This is done to determine the effect of self-confidence on students' understanding of mathematical concepts through the implementation of an independent curriculum. The following are the results of a simple linear regression analysis: This value indicates that if the self-confidence variable is 0 (zero), then the student's understanding of mathematical concepts is 21.439. b. Coefisien X1 = 1,189 This value indicates that if the self-confidence variable increases by 1 unit, it will result in an increase in students' understanding of mathematical concepts by 1.189. On the other hand, if the self-confidence variable decreases by 1 unit, it will result in a decrease in the understanding of mathematical concepts by 1.189. Based on the results of hypothesis testing in table 7, the count value is 977.721 and a significant value is 0.000 <0.05, which means that H0 is rejected and Ha is accepted. This shows that self-confidence has a positive effect on students' understanding of mathematical concepts through the implementation of an independent curriculum. The magnitude of the influence of self-confidence on students' understanding of mathematical concepts through the application of an independent curriculum can be seen from the value of the coefficient of determination as presented in table 8 below: Based on the results of the analysis in table 8, the R Square value is 0.912. Thus it shows that self-confidence to explain students' understanding of mathematical concepts through the implementation of an independent curriculum of 91.2% and the remaining 8.8% is explained by other variables not examined in this study.

DISCUSSION
Based on the results of hypothesis testing, it can be seen that self-confidence has a positive effect on students' understanding of mathematical concepts through the implementation of an independent curriculum of 91.2%. This means the application of an independent curriculum that gives freedom to explore anything with a sense of comfort and gives happiness in gaining knowledge without any pressure from anywhere so that it can foster self-confidence in the abilities one has to develop the potential that exists within oneself. The better the students' self-confidence, the betstudentsnts' understanding of mathematical concepts. The results of this study support the results of Islami & Rusliah, (2019) which show that there is an effect of self-confidence on students' understanding of mathematical concepts.
Trust is an attitude of confidence in own abilities that can make other people not feel anxious about the actions they take, and have a sense of responsibility and encouragement to excel (Dewi 2018). The nature of belief in own abilities will affect the level of individual achievement. In addition, Fitriani (2015) also revealed that self-confideinfluencese on student achievement. This is because students who have selfconfidence will always be motivated to fight for achievement to be successful in learning. With self-confidence, students will be more motivated to learn mathematics that student achievement increases optimally. In other words, self-confidence or self-confidence is an aspect that influences one's success in learning, especially in mathematics. Therefore, in the teaching and learning process, it is necessary to apply aspects of self-confidence so that students achieve success in learning.
Each student has different self-confidence or self-confidence because each student has a different character and personality. If a student has good self-confidence, the student will be active in the learning process in the classroom. Self-confidence can be seen from the activities of students in working on questions given by the teacher, answering and asking questions explaining the results of their work to other stud, ents and being able to work together with other students. Self-confidence is very important for students to achieve success in learning mathematics (Nurkholifah et al., 2018). Students who have low self-confidence or lose self-confidence, have negative feelings ave weak confidence in themselves.

CONCLUSION
Based on the results of the research data analysis above, it can be concluded that self-confidence has a positive effect on understanding mathematical concepts through the implementation of an independent curriculum of 91.2%. Therefore, the teacher should also pay attention to students' self-confidence, because the better the students' selfconfidence, the better students understanding of mathematical concepts.