The Development of Integrative Thematic Learning Tools Based on Problem Based Learning to Improve Critical Thinking of Students in Fourth Grade in Elementary School

The purpose of this research and development is to develop and describe the feasibility and effectiveness of developing integrative thematic learning tools based on Problem Based Learning in improving students' critical thinking. This type of research is research and development that refers to Borg and Gall theory. The population of this study was the fourth-grade students of elementary schools in Argomulyo Village, Banjit District, and the sample was determined by a purposive sampling of 27 students. Data were collected through observation sheets, questionnaires, and test questions. The test instrument that used able to fulfills validity and reliability, taking into account the level of difficulty, and the different power of the questions. The data analysis technique used is the n-Gain test to determine its effectiveness. The results of validating thematic learning tools based on Problem Based Learning are done by curriculum experts and learning experts. The results showed that the product development of integrated thematic learning tools based on Problem Based Learning produced is effective for use in the learning process for fourth-grade students. This is proved by the increase in student learning outcomes and students' critical thinking skills after using an integrative thematic learning tool based on Problem Based Learning.

In this study, the R&D model developed by Borg and Gall was later modified into three main steps according to Sukmadinata (2012: 184), namely (1) a preliminary study, (2) model development, (3) model testing. The study population was fourth grade students of the State Elementary School Banjit District who had implemented the 2013 curriculum, namely SDN 3 Argomulyo with 27 students. The sample was determined using purposive sampling with the consideration that SDN 3 Argomulyo as a school the 2013 curriculum implementation. Data collection tools for the development of integrative thematic learning tools using a questionnaire, namely the validation of curriculum and learning experts covering aspects of material and media.
Learning outcomes are obtained from the results of the pretest and posttest learning using LKS (student worksheets) PjBL model oriented to project appraisal, using valid and reliable test instruments, and considering the level of difficulty and different power of questions. The multiple choice instrument is given a score of 1 for the correct answer and a score of 0 for the wrong answer. Learning outcomes of skills using observation sheets. Data analysis technique to see the effectiveness between the use of PBL-based integrative thematic learning tools in learning is done by analyzing the normalized average gain value with the n-Gain formula. The n-gain analysis that will be used in this study is based on the results of the pre-test and post-test. Hake (in Sundayana, 2015: 149) revealed that in order to know the effectiveness of a learning in conceptual understanding, an analysis of the average value of normalized gain was carried out.

The Result Development of Integrative Thematic Learning Tools Based on Problem Based Learning to Improve Critical Thinking of Students in Fourth Grade in Elementary School
The Result Development of Integrative Thematic Learning Tools Based on Problem Based Learning to Improve Critical Thinking of Students in Fourth Grade in Elementary School, The following results are obtained.

Research and Information Collecting
Information was collected by observation and interviews with school principals and fourth grade SDN 3 Argomulyo teachers. The results of observations and interviews obtained information that (1) the quality of the learning process is still low. (2) The ability to think critically in low category students. (3) The ability of teachers to develop integrative thematic learning tools is still weak. (4) The systematic integration of thematic learning tools not yet prepared by the government. (5) The unavailability of integrative thematic learning tools based on the PBL approach in SDN 3 Argomulyo.

planning
Planning is done by analyzing the results of information gathering. The product to be developed is a learning tool consisting of a syllabus, lesson plans, student worksheets and assessment instruments. Furthermore, the authors systematically compile the basic competencies, indicators, and learning objectives developed in this study. The theme and sub-theme determined are theme 3, 'Care for Living Things' and sub-theme 1, 'Animals and Plants in My Home Environment' in Class IV.

Development of the Initial Product Format
The steps in developing a thematic-integrative learning tool product based on Problem Based Learning are as follows: a. Arrangement of learning devices of thematic-integrative learning tools based on Problem Based Learning The thematic-integrative learning tool product based on Problem Based Learning was developed as a learning device in the fourth grade on theme 3 (Care for Living Things), subtheme 1 (Animals and Plants in My Home Environment). The following is the initial product prototypes of the learning tools compiled. Syllabus, Learning Implementation Plan, and Student Worksheets (Cover, Preface,

b. Product Validation and Product Revision
Product validation is carried out by curriculum experts to assess the validity of learning tools in the form of syllabus and Learning Implementation Plans. Next is the learning expert, that is the material expert and the media expert, to assess whether the Problem Based Learning Worksheet is rationally valid and effective to be used to improve student learning outcomes. The first is the assessment of curriculum experts, this assessment includes the assessment of learning tools in the form of syllabus and Thematic-integrative Learning Implementation Plan based on Problem Based Learning conducted by Lecturers at Lampung University. Based on the curriculum expert test, there are a number of things that need to be improved, that are (1) learning steps must refer to Problem Based Learning, (2) time allocation must be adjusted to the division of class hours, and (3) writing on the syllabus matrix, indicators must parallel to basic competencies.
Secondly, the assessment of learning experts conducted on the Problem Based Learning Student Worksheet product consisting of material experts and media experts. The two experts are Lecturers at Lampung University. Based on the learning expert test, several things need to be improved, that are (1) The cover is designed more Journal of Education and Practice www.iiste.org ISSN 2222-1735 (Paper) ISSN 2222-288X (Online) Vol.10, No.30, 2019 interesting, (2) Core Competency needs to be added, and (3) the rice plant flow scheme in the material description needs to be clarified.
Third, is the Evaluation Validation Results, the test instrument to measure student learning outcomes before and after using teaching materials in the form of Problem Based Learning Student Worksheets, validated first with trials on 21 students in fourth grade in Public Elementary School 2 Argomulyo. from 50 questions tested there were 33 valid items. However, 30 items were used for the pretest and posttest in this study.

Preliminary Field Testing
The product trial is limited to small groups conducted to fourth-grade students in Public Elementary School 2 Argomulyo. The assessment by the small group was carried out by 9 people consisting of 3 people from the group with high initial ability, 3 people from the group with moderate ability, and 3 people from the low group. The product trial results are limited to small groups used to find out the improvement of learning outcomes, critical thinking skills, and the effectiveness of the use of integrative thematic learning tools based on Problem Based Learning. These are the following results of small group trials. a. Learning outcomes The product trial was limited to a small group conducted to fourth-grade students in Public Elementary School 2 Argomulyo. There are differences in learning outcomes before and after using a Problem Based Learning Worksheet. Improvements that occur before and after learning are calculated by the N-Gain formula, as follows: Completeness Level 55% 78% Based on the hypothesis test, the N-Gain calculation result is 0,35 in the medium category and students reach the KKM of 78% (7 students), then the Problem Based Learning-based Student Worksheet is effectively used in the fourth-grade student in Public Elementary School 2 Argomulyo.

b. Critical Thinking Ability Test Results
The results of the critical thinking ability test were obtained from student observations during the learning in the limited trial class. The following is a recapitulation of the results of students' critical thinking in small groups. 0-50 Not Good 0 0,0 Total 9 100,0 Based on the table, it can be described that the critical thinking skills of 9 students in a small group there are 1 student (11.1%) with a very good category, 5 students (55.6%) with a good category, and 3 students (33.3%) with enough categories. It can be interpreted that the ability to think critically is marked by the emergence of aspects that show indicators of critical thinking skills have been seen.

c. Victory, Ease, and Benefit Test Results
The test of attractiveness, convenience, and usefulness is done by spreading the student response questionnaire. The results of the students' responses to the Problem Based Learning Worksheet based on Problem are as follows: Problem Based Learning Worksheet based on learning is good and feasible to be developed and tested in the next stage.

Main Product Revision
Shows that there is a significant improvement in learning outcomes and critical thinking skills, so that the product does not need revision, and is worth testing in large groups.

Main Field Testing
There are differences in learning outcomes before and after using a Problem Based Learning Worksheet. Improvements that occur before and after learning are calculated by the N-Gain formula, as follows. Completeness Level 48% 85% Based on the hypothesis test, the N-Gain calculation result is 0.37 in the medium category and students reach Minimal Completeness Criteria by 85% (23 students). An increase in learning outcomes before and after using Worksheet based on Problem Based Learning in fourth-grade students in Public Elementary School 3 Argomulyo. Meanwhile, the results of the critical thinking ability test were obtained from the observation of students during the learning process in the limited trial class. The following is a recapitulation of the results of students' critical thinking skills in large groups. 0-50 Not Good 0 0,0 Total 9 100,0 Based on the table above it can be described that the critical thinking skills of 27 students in a small group there are 7 students (24.9%) with excellent categories, 13 students (50.2%) with good categories, and 7 students (24.9 %) with enough categories.
While the Test of attractiveness, simplicity, and usefulness is done by spreading the student response questionnaire. The results of the students' responses to the Worksheet based on Problem Based Learning are as follows. Questionnaire Student Response to the Worksheet based on Problem Based Learning. In the table above, it appears that the average aspect of attractiveness is 4.57 with a very interesting category, an average aspect of ease of 4.17 with the easy category, and an average benefit aspect of 4.43 with a very useful category. The results of the analysis show that the Worksheet based on Problem Based Learning product trials is extended to large groups, in general, it is very interesting, easy, and very useful for students. Thus, Worksheet based on Problem Based Learning is good and appropriate to use.

Operational Product Revision
Done after major field trials to improve the product, taking into account comments and suggestions during previous trials.

Effectiveness Integrated thematic learning tools
The product effectiveness test was conducted to see a significant increase in students' critical thinking skills Journal of Education and Practice www.iiste.org ISSN 2222-1735 (Paper) ISSN 2222-288X (Online) Vol.10, No.30, 2019 viewed from student learning outcomes before and after learning using thematic learning tools. The recapitulation of student learning data shows an increase in learning outcomes which also shows the results of students' critical thinking skills after learning to use student worksheets based on theme 3 that is 'Care for Living Things' and subtheme 1 that is 'Animals and Plants in My Home Environment'. The average pretest learning outcomes of students in grade 4 were 57 and posttest results increased to 73.3 with an average N-Gain of 0.37 (medium category).

Discussion 3.3.1 Product Development of Integrative Thematic Learning Tools Based on Problem Based Learning
This research is a research development, the development is carried out by analyzing the observational data. In the initial field study, information was obtained that (1) the quality of the learning process was still low. (2) The ability to think critically in low category students. (3) The ability of teachers to develop integrative thematic learning tools is still weak. (4) The systematic integration of thematic learning tools not yet prepared by the government. (5) The unavailability of integrative thematic learning tools based on the Problem Based Learning approach in Public Elementary School 3 Argomulyo. Therefore, the authors develop a thematic-integrative learning tool based on Problem Based Learning in the fourth grade of Public Elementary School 3 Argomulyo.
The development of this learning device pays attention to various things that must be present as provisions in making learning devices. The learning tools developed to refer to the Curriculum2013, with a scientific approach, authentic assessment, and paying attention to the three domains of student competency, which are attitudes, knowledge, and skills. The design of syntax, design, and materials and thematic-integrative learning tools based on Problem Based Learning use a thematic learning approach that is integrated with the Problem Based Learning learning model.
The stages of learning in Problem Based Learning enable students to learn independently and be able to solve problems, thereby providing meaningful knowledge and leads to improved student learning outcomes. This is in accordance with the opinion of Arends (2012: 398-399) which states the main objectives of Problem Based Learning are (a) developing thinking and problem-solving skills, (b) helping students learn to take on the role of adults and social skills (adult role behavior and social skills), and (c) help students develop skills for independent learning (skills for independent learning).

Effectiveness of Integrative Thematic Learning Tools Based on Problem Based Learning
The effectiveness of teaching material in learning is seen from whether or not the student's learning outcomes increase after using the teaching material. To determine the effectiveness of the use of thematic-integrative learning tools based on Problem Based Learning by looking at the level of learning outcomes obtained by students before and after participating in learning using the Problem Based Learning model. Effectiveness test is used to see the ability to think critically, and student learning outcomes. The effectiveness test was conducted on 27 students in the fourth grade of Public Elementary School 3 Argomulyo. Based on the effectiveness test using the N-Gain, it is obtained that the learning outcomes and critical thinking skills of students after using Worksheets based on Problem Based Learning are higher than before using Worksheets based on Problem Based Learning.
This is based on the recapitulation of student learning outcomes of large groups (page attachments) obtained an average N-Gain of 0.37 in the medium category. There is an increase in student learning outcomes before (pretest) and after (posttest) using a Problem Based Learning Worksheet. The results of the observation of critical thinking skills (attachment page) that the critical thinking skills of 27 students in a large group there are 4 students (14.8%) with a very good category. There were 18 students (66.7%) in the good category and 5 students (18.5%) in the sufficient category. Thus that there is an increase in student learning outcomes and critical thinking skills before and after using the Worksheet based on Problem Based Learning in the fourth grade of Public Elementary School 3 Argomulyo. This finding is supported by the opinion of Duch, et.al (2001: 6) that Problem Based Learning aims to help students develop critical thinking skills, analyze and solve complex real-world problems. Strengths of Development of Integrative Thematic Learning Tools Based on Problem Based Learning. And Limitations in the Development of Integrative Thematic Learning Tools Based on Problem Based Learning.

Excess the Development of Integrative Thematic Learning Tools Based on Problem Based Learning
(1) the Development of Integrative Thematic Learning Tools Based on Problem Based Learning that are developed in accordance with the 2013 Curriculum and according to students' needs. (2) Learning activities using thematic-integrative learning tools based PBL contain learning components namely problem orientation, organizing students to learn, guiding individual experiences, developing and presenting their work, and analyzing and evaluating problem solving processes. (3) The material in worksheets uses simple, clear, and easyto-understand language in constructing knowledge (4) worksheets in accordance with the objectives of making it easier for students to understand the material presented. This shows that the worksheet can motivate students and not make them bored with learning. (5) worksheet based on PBL help and simplify the learning process and improve students' critical thinking skills.

Limitations on Development of Integrative Thematic Learning Tools Based on Problem Based Learning
(1) Core competencies and basic competencies in Development of Integrative Thematic Learning Tools Based on Problem Based Learning only develop one sub-theme with 4 learning. (2) Product trials are only 4 meetings so that learning outcomes are less than optimal. (3) Limitations in compiling research instruments and research instruments that have been tested only once so as to allow errors and seriousness to respond to the instrument. (4) Population limitations in testing the effectiveness of thematic-integrative learning tools are only done in one school.

CONCLUSION
Based on the results of research on the development of thematic-integrative learning tools based on problem based learning on the sub-themes of animals and plants in my home environment of fourth grade in Public Elementary School 3 Argomulyo, Banjit District, Way Kanan District, it can be concluded as follows: 1) Product development of learning devices Thematic-integrative Problem Based Learning developed based on needs analysis, assessment of learning experts consisting of material experts and media experts, curriculum experts, teacher validation, and student responses, is declared valid as a learning tool used in the learning process in fourth grade Public Elementary School 3 Argomulyo. 2) The product development of thematic-integrative learning tools based on Problem Based Learning that is produced is effectively used in the learning process of fourth-grade students in Public Elementary School 3 Argomulyo. This is proved by the increased learning outcomes of fourth-grade students in learning the sub-theme "animals and plants in my home environment".

SUGGESTION
The development of thematic-integrative learning tools based on Problem Based Learning requires creative educators to present material, have abilities and skills, actively engage students according to low, medium, and high absorbency.