THE DEVELOPMENT OF PROBLEM BASED LEARNING DEVICE FOR JUNIOR HIGH SCHOOL NATURAL SCIENCE CLASS FOR LEARNING SUBSTANCE PRESSURE AND ITS DAILY USE MATERIAL

This research was purpoted to develop a valid, practical and effective learning devices based on problem-based learning model especially for substance pressure materials. The development model used was 4-D model from Sivasailam Thiagarajan. The research data are validity data, practicality data, and effectiveness data. The research instruments were validation sheets, practicality sheets, and effectiveness sheets. The data analysis technique used is a descriptive analysis. The results of the study are the science learning tools of SMP based on the learning model of problem-based learning on material pressure and its application in everyday life that is valid, practical and effective.


INTRODUCTION
Developing learning device must meet the criteria of good quality learning devices. The quality of learning tools is determined by valid, practical and effective criteria. The learning tools developed must be in accordance with the 2013 curriculum. http://ijeds.ppj.unp.ac.id/index.php/IJEDS International Journal of Educational Dynamics  Desember 2019 p_ISSN 2655-4852 e_ISSN  The ideal learning design and expected by the 2013 curriculum is the learning process design that balances soft skills and hard skills.
Substance pressure an its use in daily life is one of he materials taught in Natural Science classes at Junior high school. Substance pressure is commonly found in daily life. Various problems in the daily lives of students can be explained by the concept of pressure, for example the cause of ear pain when diving deep. This material is very important for students to understand scientifically through learning either through experimental activities or through the investigation of literature on the phenomena contained in the material. Therefore teachers need a good learning plan with teaching materials that are in accordance with the demands of the curriculum.
The results of the observation carried out in July 2018 found that the science learning devices at SMPN 1 Mapat Tunggul had been prepared in accordance with the demands of the 2013 curriculum. The RPP that was prepared had organized students in group activities and discussions with fellow students. Learning design has followed the syntax of certain learning models. However, after observing the steps in the main activities, student activities are more focused on the activity of recording all information about the material pressure of solids, liquids and gases from the textbook. In addition to the lesson plans, teachers must also prepare teaching materials to support classroom learning. Through observations, it was found that teaching materials used at SMPN 1 Mapat Tunggul are national text books, so students are less interested in science lessons and more silent while learning, the teacher complains of the difficulty of activating students in learning activities. Information obtained through observation and interviews with science teachers showed the same conclusions as the results of student analysis conducted at school. Based on the results of student analysis that has been done, it is obtained that 77% of students do not actively participate in class discussion activities, 86% of students are bored studying science with the lecture method and 74% of students are happy if science lessons are associated with daily natural phenomena.
The conclusion of these problems is that teachers need to develop learning devices that meet valid, practical and effective criteria in accordance with the demands of the 2013 curriculum. The learning tools developed must be based on scientific learning models so that they are more motivating for students to learn and be able to International Journal of Educational Dynamics   interests and is suitable for building intellectual abilities.
The Ministry of Education and Culture (2014) stated that problem-based learning is a learning model that presents contextual problems that stimulate students to learn in groups to solve problems from real-world problems. Oon-Seng Tan (in Abidin 2014) argues that PBL is student-centered where unstructured problems (real world problems or complex problem simulations) are used as starting points and anchors for the learning process.
Based on the description, this study produces a science learning device for junior high school learning model of problem-based learning that is valid, practical and effective on material pressure and its application in everyday life

METHOD
The design model used in this research was 4D model which was developed by Sivasailam Thiagarajan (1974). Thiagarajan (in Trianto, 2009) called it 4D because the model development process is divided into 4 stages: define, design, develop, and disseminate.
In this research the instruments used were validity sheet, practicality sheet and effectiveness sheet.The techniques of analysis were product validity analysis, practicality analysis, and effectiveness analysis. To calculate the devices' validity and practicality, the researcher percentage wise analysed the obtained score of categories from validity testing. A device was considered valid if the score was above 60 %. The validity tested in the development of learning tools is content validity, construct validity, language validity, and graphic validity. Content validity relates to the content and format of the learning tools developed. Construct validity is concerned with the construction or structure and presentation of the developed learning tools. The validity of the language regarding the language and writing used and the validity of the graphics related to the printout, for example, the layout of the cover, the arrangement of letters, type letters and others. The device developed in development research is said to be practical if we can apply the device in the field and the level of implementation is in a good category. They say a product to be practical if people can use the product.
According to Aida Fariroh's research (2015), practicality based on student responses of 81.81 and teacher responses of 100 got very practical criteria. According to N Za'ba and S Prabawanto (2019), modules developed based on PBL that are practical can facilitate students learning mathematics. Device practicality was also analysed in percentage as presented in Table 1. Effectiveness shows the level of success in achieving a goal. The effectiveness tools are determined by the competency assessment of attitudes, knowledge, and skills carried out at each meeting. Device effectiveness was also analysed in the same manner.
A device was considered effective if 85% students classically completed attitude, knowledge and skill competencies.

The Result of Validity Testing
In the validation activity, experts and practitioners are asked to assess the learning tools that have been made. Assessment includes content validity, construct validity, Language validity and graphic validity. The validator is asked to provide an assessment and suggestions for improvements to the syllabus, lesson plans, modules and assessments that have been designed. Based on the assessment conducted by the validator, the results obtained in Table 2. Based on the data in Table 2, we get the results that the learning device is in the valid category. We can conclude it that the devices that have been developed are appropriate and meet the valid criteria and are suitable for testing.

3.2.The Result of Practicality Testing
Data on the practicality of learning tools are obtained based on assessment during the learning process using the lesson plans that have been designed, teacher's assessment of learning tools that are developed, and students' assessment of the modules they use during learning activities. The results of the practicality of the developed learning tools can be seen in the following table 3. Based on Table 3 we can conclude it that the learning device based on the problem-based learning model of learning on material pressure substances and its application in daily life that is developed is very practical to be used in the learning process.

3.3.The Result of Effectiveness Testing
Data on the effectiveness of learning tools are obtained based on student learning outcomes which include attitudes, knowledge and skills competencies. The results of the effectiveness of the learning kit at the trial stage can be seen in Table 4. effectiveness of learning tools are also obtained based on student learning outcomes in the class deployment. The results of the effectiveness of learning tools in the deployment class can be seen in Table 5. Based on Table 5 we can conclude it that the learning tools developed already meet the effective criteria for the learning process.

3.4.Discussion
The The results of the practicality of learning tools based on teacher responses to the syllabus, lesson plans, modules, and assessments are between 93.8% to 100%.
According to Riduwan (2009) if the practicality value is over 80% then the category of learning tools developed is very practical. Therefore, based on the teacher's response questionnaire, the learning tools developed are very practical.   teacher's assessment, the module makes it easy to guide students to implement problembased learning, makes it easy to convey facts, concepts, principles, and procedures and the pictures in the module to help the teacher make it easier for students to remember the material.

International Journal of Educational Dynamics
Besides the teacher's response questionnaire, we got the practicality of the module through the students' questionnaire responses as module users. Based on the questionnaire responses of students got module practicality of 86.9%. According to students, the module makes it easy to understand the relationship between the concept of pressure and its application in daily life and the problems presented in the module are simple and interesting to learn. According to Riduwan (2009), if the practicality value is over 81% then the category is very practical. Therefore, it is concluded that the module developed is very practical for the study of substance pressure and its application in everyday life. Based on these reviews, we conclude that the learning tools based on problem-based learning on substance pressure and its application in daily life are very practical in junior high school science learning.
We see the effective tools in this study from the acquisition of the value of student learning outcomes from aspects of competence in attitudes, knowledge, and skills.  R Isna, et al (2018) states that the implementation of PBL-based modules can train students' speaking skills through presentation activities. Heru Edi Kurniawan (2016) through research into the development of PBL-based devices can also improve students' psychomotor abilities. Ratna Ningsih, et al (2016) also resulted in PBL-based learning tools effectively improving the performance of high school students in preparing reports. Classroom action research conducted by Yosico Indagiarmi and Abd Hakim (2016) also resulted in an increase in the value of student skills after applying problembased learning.

CONCLUSION
Based on the description above it can be concluded that the learning device developed has been valid based on the validator's assessment consisting of 3 expert validators and 2 validator practitioners. The valid learning tools are syllabus, lesson plans, modules and assessment tools consisting of attitude, knowledge and skills assessment. The learning tools developed are very practical. Practicality of the device (Syllabus, lesson plans, modules and assessment tools) is obtained through the teacher's response questionnaire. The practicality of the lesson plan is also obtained through observing the implementation of the lesson plan in class and the practicality of the module is also obtained through student questionnaire responses after using the module.
Learning tools developed effectively. The effectiveness of the use of the device is based on student learning outcomes for attitudes, knowledge and skills competencies acquired at the testing and dissemination stages