The results of the mathematics learning of junior high school students have not been satisfactory. This is due to the low understanding of students' mathematical concepts. The purpose of this research is to identify the influence of cooperative learning model and learning style towards the understanding of the mathematical concepts of Junior High School students. The method is factorial experiments with 2 x 3 and sample of the study is 60 students of 8th grade junior high school. The analysis results of variance (ANOVA) indicate the following: the use of cooperative learning model of type Student Team Achievement Division influenced the understanding of the mathematical concepts significantly, there is an significant influence of the learning style towards an understanding of mathematical concepts, and there is also a significant influence of the interaction of cooperative learning model of type Student Team Achievement Division and learning style towards the understanding of mathematical concepts. So it can be concluded that the cooperative learning model can improve understanding of students' mathematical concepts and learning styles is a individual differences of learning students in absorbing mathematics subject matter. We hope that this study can be beneficial for further research to improve student's achievements in mathematics.

Professional teacher performance is the hope of the Indonesian community to teach the next generation well. The research aimed to find out a direct and an indirect effect of exogenous variables toward endogenous variables. The sample research amounted to 360 public high school teachers in Jakarta. Smart-PLS with r > .70 is used to gain the validity and reliability test required to analyze research data. The results showed that there were: direct positive influences of organizational culture and personality on the trust and decision-making; the direct positive influence of organizational culture, trust, and decision-making on job performance; and also there was an indirect influence of organizational culture through trust on teachers’ job performance; an indirect influence of organizational culture through the decision-making on teachers' job performance; personality through trust on teachers’ job performance. Trust and decision-making as variables intervening did not have an effective influence on job performance, because pandemic has changed the situation of teacher performance.

<em>This experiment is to know the understanding of the mathematical concept students are reviewed from a model of cooperative learning and motivational learning. The research Model uses a 2 x 2 factorial design. The research sample is 60 Grade 9 students from first junior high school, South Jakarta academic year 2018--2019. The two-way Analysis of variance (ANOVA) is used in this study. The effectiveness of the learning management is determined by the calculation of effect size, while the results of the study are as follows: There is a influence of cooperative learning model interaction and motivation to learn to understand mathematical concepts, Influence of cooperative learning model to understand the concept of mathematics, the influence of motivation to learn to understand the concept of mathematics, and learning model of cooperative learning the type of Student Teams Achievement Devision (STAD) has High effectiveness towards understanding students ' mathematical concepts. With the conclusion that understanding the concept of mathematics in junior high school is influenced by the use of cooperative variation and learning motivation of students. This research is expected to be beneficial for further research to improve the mastery of students ' mathematical concepts.</em>

Natural science learning achievement is an essential factor in learning outcomes. This research investigated an experimental study that aimed to improve concept science test result in online learning through Jigsaw cooperative learning model and learning style. The research involved the sample of 80 students from junior high school in South Jakarta, Indonesia divided into two groups: the experimental class and the class control. Raw data were statistically analyzed using the two-way variance technique at the .05 significance level. The findings revealed an effect between cooperative learning on natural science learning achievement, learning interest in natural science learning achievement, and interaction between cooperative learning and learning interest in natural science learning achievement. As a result, cooperative learning type Jigsaw shows a significant impact and had a good test result on natural science learning achievement. Therefore, the research suggests that Jigsaw cooperative learning is well suited to use as a learning model among junior high school students based on effect size test results.

This study aims to draw up a work program and guidelines for the state vocational high schools. This research used a mixed method (quantitative and qualitative) with SWOC analysis. Qualitative methods were used to obtain components of strengths, weaknesses, opportunities, and challenges through group interviews, observation, and the previous year's program documents. The sample consisted of 150 personnel involving the head of departments, school supervisors, headmasters, teachers, administration staff, guardianship of student organizations, alumni representatives, and parent representatives. Quantitative data collection was conducted through instrument in the form of questionnaires using a model of Likert scale. The obtained data were then grouped into components of the strengths, weaknesses, opportunities, and challenge of the schools. All of those components are tested first on their validity and reliability with 100 personnel as a sample of quantitative analysis. These four components are then analysed by quantitative Factor Analysis method based on Internal Factor Analysis Summary (IFAS) and the External Factor Analysis Summary (EFAS) to get the resultant value. The resultant value was then filled into Cartesian diagrams resulting in the organization's position. The final result of the research is: The stages of strategic planning in the Indonesian vocational high schools, dominant factors of the schools at present conditions based on the resultant calculation, and the future strategic planning for vocational high schools in Indonesia. It is hoped that the result of this study can be beneficial for the policymaker, stake holder, school principals, and other researchers in related fields.