This study was conducted to determine the effectiveness of multiple representation-based learning (MRL) model compared to discovery learning (DL) model and problem based learning (PBL) model in terms of students' initial abilities. The factorial design was used in this study. The selection of samples in this study was done through a random sampling technique. Three X classes of the same school was chosen. The three classes applied different learning model. The first class employed the MRL, the second class used the DL model, and the last class adopted the PBL model. Overall, the number of samples involved in the study was 117 students. The results of the study showed that the conceptual understanding of students learning using MRL was significantly different from the students learning to use problem-based learning with significant differences in N-gain was 0.0004, but not significantly different from the students using discovery learning. This finding showed that MRL is the most effective model for increasing the conceptual understanding of students with "low" and "moderate" initial ability compared to PBL and DL.

Misconception is one of the most widely researched topics in science education, including chemical education. This research aims to apply simple graphical visualization tool named Winplot for a learning exercise activity and explore its potency to counter misconceptions about orbitals and quantum numbers. Misconceptions that were countered in this research are the existence of orbitals in atoms and the relationship of magnetic quantum numbers to orbital orientation. This quasi experimental research using pre-test-post-test control group design was conducted to 43 first-year undergraduate students as control class and 45 as experimental class of chemical education at the University of Lampung. The students’ pre-existing concepts were analyzed using a pre-test instrument and explored further using in-depth interview. Then, after implementing a learning exercise activity, the conceptual changes were analyzed using a post-test instrument. The results showed that students in experimental class had significant conceptual changes compared to control class. Applying this computer-based strategy is highly recommended to guide students in understanding chemical concepts, especially the topics of orbitals and quantum numbers. Key words: learning exercise, first-year undergraduate, computer-based learning, misconceptions, quantum chemistry.

The quality of international education is measured through PISA and TIMSS results and the member countries are very concerned about their students' ability to work on PISA and TIMSS. Countries with low PISA and TIMSS ratings indicate that students' science process skills in this country are low, including in Indonesia. Therefore, this research needs to be done to see the characteristics of science process skill (SPS) of junior high school students, especially in Indonesia. This study involved 9th-grade students of the academic year 2016/2017 in three randomly selected districts. The number of subjects involved in the study was 120 randomly selected respondents. The research was conducted by survey method, by giving SPSs questions to respondents. The results showed that the SPS of junior high school students in Lampung Province-Indonesia is low. Students from schools in the capital and school areas close to the provincial capitals have the characteristics of SPSs on "observing" and "classifying" indicators in the "moderate" category. Students from distant areas of the provincial capitals, the characteristics of their SPSs are "low", for all indicators (observing, classifying, predicting, interpreting, and communicating).

The Effect of Socio-Scientific Issues in Improving Critical Thinking Ability on Electrolyte and Non-Electrolyte Solutions. This research was aimed to describe the effect of socio-scientific issues in improving critical thinking ability on electrolyte and non-electrolyte solutions. The cluster random sampling technique was used for the selection of samples, obtained X IPA 1 as experimental class and X IPA 4 as control class. The method is quasi-experimental design with a pretest posttest control group design. The effect of socioscientific issues was analyzed by the differences of two averages on n-Gain and the effect size test. The results of the study showed that the average n-Gain of students' critical thinking ability in the experimental class was' high ', and the effect size was' large'. The conclusion of this research is that socioscientific issues based learning has a positive effect in improving critical thinking ability in electrolyte and non-electrolyte solutions material.Abstrak: Pengaruh Isu Sosiosaintifk dalam Meningkatkan Kemampuan Berpikir Kritis pada Materi Larutan Elektrolit dan Non-Elektrolit. Penelitian ini bertujuan untuk mendeskripsikan pengaruh isu sosiosaintifik dalam meningkatkan kemampuan berpikir kritis pada materi larutan elektrolit dan non-elektrolit. Teknik cluster random sampling digunakan untuk pemilihan sampel, diperoleh kelas X IPA 1 sebagai kelas eksperimen dan kelas X IPA 4 sebagai kelas kontrol. Metode dalam penelitian ini yaitu kuasi eksperimen dengan desain penelitian pretest posttest control group design. Pengaruh isu sosiosaintifik dianalisis menggunakan uji perbedaan dua rata-rata pada n-Gain dan uji effect size. Hasil penelitian menunjukkan bahwa rata-rata n-Gain kemampuan berpikir kritis siswa pada kelas eksperimen berkriteria 'tinggi', dan effect size 'besar'. Kesimpulan penelitian ini yaitu pembelajaran berbasis isu sosiosaintifik berpengaruh positif dalam meningkatkan kemampuan berpikir kritis pada materi larutan elektrolit dan non elektrolit.Kata kunci: isu sosisaintifik, kemampuan berpikir kritis, larutan elektrolit dan nonelektrolit 296

This study developed a knowledge assessment instrument of three tier diagnostic tests based on higher order thinking skills (HOTS) which aims to diagnose students' understanding in higher-order thinking and reduce misconceptions. The research method uses ADDIE (Analysis-Design-Develop-Implement-Evaluate) and the subject is class VII junior high school students with 2017 odd semester curriculum materials. This study used HOTS-based knowledge assessment instruments of three tier diagnostic tests of 20 items. The results of the instrument expert validation test based on aspects of content, construct, and language assessment have an average score of 90, 88, and 89 with a proper assessment. The data were analyzed using rasch model and the item reliability index was 0.89, the reliability index of the respondents was 0.91, and Cronbach's alpha value was 0.93, which meant the reliability of the questions obtained was good. The results of the students 'answer patterns are six criteria: understanding concepts, misconceptions (+), misconceptions (-), misconceptions, guessing / lack of confidence / luck, and not understanding the concepts used to diagnose learners' understanding in measuring high-level thinking skills (HOTS) which is integrated with the dimensions of factual, conceptual and procedural knowledge. Misconceptions that occur in students have three criteria, namely misconception (+), misconception (-), and misconception, and the most experienced by students is a misconception (-) in the C4 cognitive level which is integrated with the conceptual knowledge dimension on the substance characteristic material . This misconception (-) can be reduced through the correct concept with the right reasons.

Several studies have shown that mental models can affect a student's ability to perform reasoning on external representation faced. Student mental models are generally used to thinking in order to solve the problem. This study aims to look at the characteristics of mental models beginning of students in understand the concept of atomic structure. Samples were taken at random from the students of Department of Mathematics and Natural Sciences, class of 2012 with the grouping based on students' prior knowledge. The number of samples involved as many as 72 people consisting of students with the prior knowledge of high, medium, and low. Diagnostic tests are used to see the essays shaped the emergence of mental models.  The results showed that for all groups of prior knowledge, mental models beginning of students in understand the concept of atomic structure is still dominated by verbal mental model with the category of "very bad" and "bad" or the characteristics of mental model "formless/not clear" and mental model "intermediates_1." These results imply that the mental models of students can be used as a reference in setting learning to help students in solving problems related to the three levels of chemical phenomenon. To build a mental models of students towards a better, should be designed study involving interconnected between the third-levels of chemical phenomenon (macro, sub-micro, and symbolic).

The Effect Of SiMaYang learning In Improving Students Creative Attitudes on the Electrolyte Solution and Non-Electrolyte Solution. The research aims to describe the influence of the SiMaYang learning model in improving students' creative attitudes to electrolyte and nonelectrolyte solution materials. The method of this research is quasi-experimental with pretestposttest control group design. The population in this study were all students of class X IPA High School Bandar Lampung. The sample selection was done by cluster random sampling so that the class X IPA 2 was obtained as the experimental class and class X IPA 4 as the control class. The results showed that differences in the two n-Gain creative attitudes of students in the experimental class had high criteria. The size of the influence of the SiMaYang learning model which has the results as a "big" category with the "high" n-Gain criteria. Based on the hypothesis testing, it can be concluded that the SiMaYang learning model has a high influence on improving students' creative attitudes.Abstrak: Pengaruh Pembelajaran SiMaYang dalam Meningkatkan Sikap Kreatif Siswa pada Materi Larutan Elektrolit dan Non-Elektrolit. Penelitian ini bertujuan untuk mendeskripsikan pengaruh model pembelajaran SiMaYang dalam meningkatkan sikap kreatif siswa pada materi larutan elektrolit dan non elektrolit. Metode penelitian ini adalah kuasi eksperimen dengan pretest postest control group design. Populasi dalam penelitian ini adalah seluruh siswa kelas X IPA SMA Bandarlampung. Pemilihan sampel dilakukan dengan cara cluster random sampling sehingga diperoleh kelas X IPA 2 sebagai kelas eksperimen dan kelas X IPA 4 sebagai kelas kontrol. Hasil penelitian menunjukkan bahwa perbedaan dua rata-rata n-Gain sikap kreatif siswa pada kelas eksperimen memiliki kriteria tinggi. Ukuran pengaruh model pembelajaran SiMaYang memiliki hasil kategori "besar" dengan kriteria n-Gain "tinggi". Berdasarkan pengujian hipotesis, dapat disimpulkan bahwa model pembelajaran SiMaYang memiliki pengaruh yang tinggi dalam meningkatkan sikap kreatif siswa. Kata kunci : model pembelajaran SiMaYang, sikap kreatif , larutan elektrolit dan non-elektrolit 321

The importance of this research is to get to know the students' perceptions and motivation of the prospective chemistry teachers in facing online learning during the Covid-19 pandemic. The research design used was descriptive qualitative research. The research was conducted on students of the Chemistry Education Study Program FKIP University of Lampung in 2017, 2018, and 2019. Data collection was carried out by using a questionnaire by means of google form and learning record data in the online data-log mode edusmart.fkip.unila.ac.id. and vclass.unila.ac.id. The results indicated that (1) the interaction pattern between the lecturers and students was quite good in terms of giving assignments and discussions. In terms of feedback and learning reflection, it, however, needs to be improved (2) Students' perception of online learning is less positive, this is indicated by the number of students who are disappointed because of learning methods un-interactive, (3) students are still not motivated yet to take online lectures due to limitation of internet signals and seem to consider it as assignments only.