The main aim of this study is to develop a useful, valid, and reliable two-tier proportional reasoning skill test for middle school 7th and 8th-grade students. The research was carried out using the sequential explanatory mixed method. The study group of this research comprised of 391 (n[subscript 7th-grade]=223, n[subscript 8th-grade]=168)…

In this cross-national study, we explore the different ways of reasoning-and-proving (RP) presented in three 8th grade textbooks, one from each country: Turkey, Norway, and Slovakia. While the analysis revealed that all three textbooks contain similar numbers of problems involving some form of RP, differences exist in terms of the dominating ways…

This study aims to design mathematical literacy instruments that have evidence of content and construct validity and are reliable for use as an assessment for learning. The research involved eight experts as instrument validators and 273 eighth-grade students of junior high school in Yogyakarta Province. The results showed that the ten…

Science process skills are an important part of scientific inquiry that need to be monitored so that pupils can improve their skills to do science. Although there are several science process skills tests mentioned in the literature, we decided to develop an online one in order to improve the usefulness of the test and enable autoscoring to reduce…

The aim of this study is to develop a theoretically sound, valid, and reliable scale to examine seventh and eighth grade students' attitudes towards so-called skill-based mathematics questions (SBMQ). The sample of the study was 820 seventh and eighth grade students at three different middle schools in Etimesgut District of Ankara Province. A…

The aim of this study is to develop a valid and reliable astronomy attitude scale for secondary school students. The method of this research is a scale development study. The study group of the research consists of 300 students studying in 3 different secondary schools in Turkey in the first semester of the 2022-2023 academic year. A 32-item…

The aim of this study is to examine 8th grade students' Van Hiele geometry thinking levels, proof writing and justification skills. The research was carried out with sixteen eighth grade students of a private school in Sivas. Participants were selected based on an easily accessible sample. The data were collected from the students who participated…

This study aims to develop a valid and reliable achievement test to measure the achievement of eighth-grade students in the "Seasons and Climate" unit of the science course. The research was carried out using a survey model. The study group consists of 298 eighth-grade students studying in various cities in Turkey in the 2020-2021…

Background: Authentic situations are considered a source of learning due to their real world relevance. This can encourage learners to acquire new knowledge. Increasing digitisation and associated resources, such as professional development opportunities for teachers, technology tools, or digital equipment for schools enable the development and…

We present a case study of proving by three 12-13-year-old students with different levels of mathematical giftedness. After analysing students' proofs, we conclude that: there was a relation on the consistency and the students' levels of mathematically giftedness, being the least consistent the student not mathematically gifted and the most…

Climate change in coastal areas is a complex problem that involves value systems and requires various scientific disciplines. Integration of Science, Technology, Engineering and Mathematics (STEM) approach is needed in learning so that it can train students to think holistically, structured and systematically. This research was carried out with…

In this paper, Harel and Sowder's proof schemes of taxonomy were applied for identifying eighth grade students' learning of proof and proofing. This study aimed to examine what kind of proof schemes are used in geometry and measurement learning areas and student's skills in giving proof and their opinions about proof. Qualitative methods were…

This study focused on improving students' learning mathematical of proofs and proving by using combinations of proof strategies that span different levels of understanding of proof structure; we refer to these as 'level-spanning proof-production strategies'. We analysed the level-specific proof-production strategies evident in the lessons and…

In this study, the aim was to develop a measurement tool that would provide a valid and reliable assessment of secondary school students' mathematical resilience skills. The research was conducted with a sample of 229 students. To ensure the content and face validity of the scale, expert opinions were initially sought, and the scale was revised…

This study aims to produce a jumping task in the form of a student worksheet which is valid and practical. Design research in the form of development studies was chosen in this study which consist of preliminary stage and prototyping stage. Data were collected by walk through, test, questionnaire, and interview. Data were analyzed descriptively.…