Solving problem is not only a goal of mathematical learning. Students acquire ways of thinking, habits of persistence and curiosity, and confidence in unfamiliar situations by learning to solve problems. In fact, there were students who had difficulty in solving problems. The students were naive problem solvers. This research aimed to describe the thinking process of naive problem solvers based on heuristic of Polya. The researcher gave two problems to students at grade XI from one of high schools in Palangka Raya, Indonesia. The research subjects were two students with problem solving scores of 0 or 1 for both problems (naive problem solvers). The score was determined by using a holistic rubric with maximum score of 4. Each subject was interviewed by the researcher separately based on the subject’s solution. The results showed that the naive problem solvers read the problems for several times in order to understand them. The naive problem solvers could determine the known and the unknown if they were written in the problems. However, they faced difficulties when the information in the problems should be processed in their mindsto construct a mental image. The naive problem solvers were also failed to make an appropriate plan because they did not have a problem solving schema. The schema was constructed by the understanding of the problems, conceptual and procedural knowledge of the relevant concepts, knowledge of problem solving strategies, and previous experiences in solving isomorphic problems.

Online learning could have negative impacts on learning processes and outcomes. The condition needed to be resolved through the implementation of appropriate online learning approaches. The research was aimed at describing the effectiveness of the implementation of asynchronous and synchronous online learning approaches in students’ learning outcomes and skills of using Microsoft Excel on the Advanced Statistics of Mathematics Education Department from one of the universities in Central Kalimantan. The learning approaches were integrated with mathematics problems, Minitab software and Microsoft Excel, and videos. The research design was experimental research using a one-group posttest-only design. The subjects were chosen by clustered random sampling. They were 18 students of the department in the 2020/2021 academic year. The instruments were a lesson plan, several videos, textbooks, e-books, questionnaires, mathematics problems, mid-test, and final-test. The students learned using textbooks, e-books, and videos and solved the problems independently. Then, they discussed the solutions online in groups through their WhatsApp group (asynchronously). The problem solutions were presented by the students using a class on WhatsApp or video conference platforms (synchronous). The authors collected data by administering the questionnaire and the tests and analyzed the data using a -test and a Wilcoxon test. The results showed that the implementation of the approaches was effective in enhancing the learning outcomes and skills of using Microsoft Excel. Furthermore, most students positively responded to learn independently and all the students positively responded to analyze data using the software.

Using statistical software only or Excel only was not effective to increase the learning achievements of undergraduates. The research aimed to describe the effect of using Minitab and Excel with teaching teams toward the undergraduates' achievements of Advanced Statistics course. The research design was an experimental study. The research was conducted in nine stages. The participants were all mathematics education undergraduates from one of the state universities of Palangka Raya in three academic years, i.e. from 2015/2016 to 2017/2018. The instruments were lecture plans, midterm and final tests, and textbook of Advanced Statistics. The conclusion was drawn using covariance analysis and t-test of normalized gain. The research result showed that implementation learning of Advanced Statistics integrated Minitab and Excel with teaching teams increase the undergraduates' achievements in which the normalized gain was more than 0.3 (moderate increasing). In addition, the increase was also indicated by the average differences of the final and the initial scores at the first, the second, and the third years were 7.0, 12.5, and 19.4 respectively. The increase consistently occurred for the three academic years with a confidence level of 95%. The lecture plans could be used as an alternative way to teach Statistics courses.

Problem solving is important for mathematical learning because it enables students to enhance high thinking skills and positive attitudes. This research aimed at describing and comparing the abilities of junior high school students in grade VIII from one of the regencies/cities in Central Kalimantan (Indonesia) in solving mathematical problems based on schools' accreditations (A, B, C, and unaccredited), and schools' status (public and private). The researcher gave three mathematical problems to the students from 20 samples of schools. The schools were randomly selected from the population consisting of 62 junior high schools. Each student's solution was scored using a holistic rubric. The scores were summarized using some statistics represented in tables and graphics and were analyzed using a Kruskal-Wallis nonparametric test because the data were not normally distributed. The finding indicated that the average scores of the public and private schools' students were 4.71 and 3.49 (scale 0-12), respectively. Based on the percentages, namely 1.91% and 39.66%, the students were classified as good and naive problem solvers, respectively. Further test revealed that the students from the A-accredited public schools significantly achieved the highest score for problem solving skills. Meanwhile, the students in the A-accredited and the unaccredited private schools did not show a significant difference in the skills. Similar result was also found in the public schools which were accredited B and C, and unaccredited. Keywords: Accreditation levels; good problem solvers; mathematical problems; naive problem solvers; problem solvingTo cite this paper (in APA style): Mairing, J. P. (2017). Students' abilities to solve mathematical problems according to accreditation levels.

Students have ability to analyze data if they practiced to solved problems/projects that are related to analyzed and made conclusion from research data. The aim of this research was to develop the students worksheets of data analysis based on the problems and projects that can help students to have ability analysis research data. The development of the students worksheets used Plomps stages. Results of students workshets implementation showed that those can help: students to have meaningful understanding, like the analysis data lecture, have motivated individually to learned concepts of data analysis and solved the problems and projects in students worksheets, actived in learning process, and had ability to analyzed data by Minitab and Microsoft Excel.   Mahasiswa dapat memiliki kemampuan menganalisis data jika mahasiswa berlatih menyelesaikan masalah dan proyek yang berkaitan dengan cara menganalisis dan menarik kesimpulan dari data penelitian. Tujuan penelitian ini adalah mengembangkan Lembar Kerja Mahasiswa. Analisis Data berbasis masalah dan proyek yang dapat membantu mahasiswa memiliki kemampuan dalam menganalisis data penelitian. Pengembangan Lembar Kerja Mahasiswa ini menggunakan tahap-tahap Plomp. Subjek penelitiannya adalah 24 mahasiswa Pendidikan Matematika Fakultas Keguruan dan Ilmu Pendidikan Universitas Palangka Raya. Hasil implementasi menunjukkan bahwa penggunaan Lembar Kerja Mahasiswa dapat mendorong mahasiswa untuk: memiliki pengetahuan bermakna, (b) menyenangi matakuliah Analisis Data dan metode belajar yang digunakannya, termotivasi untuk belajar dan menyelesaikan masalah dan proyek dalam Lembar Kerja Mahasiswa secara mandiri, aktif selama perkuliahan, dan memiliki kemampuan dalam menganalisis data menggunakan Minitab dan Microsoft Excel.