Among three levels of chemical representation, the sub-microscopic level is the most difficult to learn by students. To solve the problem, it is assumed that the concept of the discontinuous nature of matter or particle concept should be mastered initially by students before they learn sub-microscopic representations of further chemical phenomena. 131 junior high school students from two schools participated in this study. The study was carried out by implementing structureoriented chemistry teaching on the particle concept that was assisted by the courseware and was continued by teaching the changing state of matter. The research instruments were written tests, questionnaire, observation sheet and interview guideline. Research data were collected before and after the use of the courseware, as well as before and after the teaching of the changing states of matter. The results show that the use of the courseware increases students' understanding of the particle concept for both male and female groups. Meanwhile, particle concept only affects the students' understanding of sub-microscopic representations of the changing states of matter in general and based on gender.

No abstract

Penelitian ini bertujuan untuk mengidentifikasi dampak PBL terhadap peningkatan kemampuan kognitif dan kreativitas peserta didik. Metode penelitian yang digunakan adalah kuasi eksperimen One Group Pretest-Postest Design, dengan subjek penelitian 38 orang peserta didik kelas XI di SMAN 24 Kota Bandung. Peserta didik dibagi dalam tiga kategori kelompok kemampuan yaitu tinggi, sedang dan rendah. Peningkatan hasil belajar dihitung menggunakan N-gain. Hasil penelitian menunjukan bahwa model pembelajaran ini dapat meningkatkan kemampuan kognitif peserta didik dengan kategori tinggi (%N-gain = 74,05%). Pencapaian dari aspek kelancaran berpikir kreatif (%N-gain = 84,04), keluwesan (%N-gain= 87), orisinalitas (%N-gain= 89), merinci (%N-gain= 72,05), dan menilai (%N-gain= 51,06). Peningkatan bertindak kreatif dari aspek kelancaran (%N-gain=80,74%), keluwesan (%N-gain=91,56%), orisinalitas (%N-gain=83,28), merinci (%N-gain=72,76) dan menilai (%N-gain=89,64). Terdapat hubungan berkategori kuat antara kemampuan kognitif dengan berpikir kreatif (r = 0,602), terdapat hubungan lemah antara kognitif dan bertindak kreatif (r = 0,367) dan hubungan berpikir kreatif dan bertindak kreatif berkategori cukup (r = 0,424). Produk kreatif yang dihasilkan peserta didik berupa alat digester biogas sederhana.

This research aim is to reveal the components of Educative Curriculum Material (ECM) and its impacts on the chemistry teachers' instructional performance and learners' achievement. This study applied the experimental method with matching only pretest-posttest control group design. A total of 36 junior chemistry teachers as the experiment group, and 36 senior chemistry teachers as the control group, and were selected by purposive-sampling. The sample of learners is chosen randomly. They consisted of 64 people as an experimental group and 64 people as a control group from different High School. The research instruments were a questionnaire, form of the analysis lesson plan and observation instructional performance, the items of teacher knowledge and learners' achievement. Data were analyzed qualitatively and quantitatively through t-tests and Normalization-Gain. The research findings indicate that (1) ECM components that effectively enhance knowledge of chemistry teachers are curriculum, chemistry content, instructional strategies, professional development, and academic skills.(2) Understanding pedagogical and professional knowledge of junior chemistry teachers as ECM users and trained better than senior chemistry teachers who do not use ECM. (3) The instructional performance of junior chemistry teachers who use ECM is better than senior chemistry teachers both in their planning and implementation. (4) The learner's achievement that learns from teacher used ECM increased higher significantly than those who did not. Based on these findings, it can be concluded that the ECM effectively improves on chemistry teachers' instructional performance and learners' achievement. Therefore it is recommended that Chemistry Teacher Group Discussion use the ECM.

This study aims to build students' creative thinking skills using problem - based learning in handling staple food waste. The research methods are development and research with the stages of design, development, and evaluation. This research was conducted at a private high school in Tangerang Regency. The research was involved thirty students of Class XI IPA in the second semester of the 2019/2020 school year and was connected through the WhatsApp group. The research instrument used Student Worksheets (LKS) in the form of a test essay for nine items that have been validated to measure students’ creative thinking skills. The research data were analyzed quantitatively by using Microsoft Excel and qualitative-  descriptive. The results of the students' creative thinking skills showed the percentage of fluency (31.66%), flexibility (35.18%), elaboration (58.33%), and evaluation (54.88%) indicators, the average percentage was 45.01% categorized as medium. The conclusions drawn are the creative thinking skills that emerge after using problem-based learning are fluent thinking, flexibility thinking, evaluative thinking, and elaborative thinking.