Types of Justification in Interdisciplinary Mathematical Modeling Activities

Abstract

This study aimed to examine the types of justifications presented by 8th-grade middle school students during interdisciplinary mathematical modeling activities. Furthermore, it addresses how these justifications become visible at different stages of the modeling process and in the context of mathematics and science. The research was conducted using a case study design and qualitative research method. The study group consisted of eight 8th-grade students enrolled in the second semester of the 2024–2025 academic year, selected using purposeful sampling. Data were collected from interdisciplinary mathematical modeling activities involving mathematics and science disciplines through video recordings, audio recordings, and students’ written outputs. In the data analysis, students’ oral and written statements were examined within an argumentation-based framework, and justification components were identified and classified according to the relevant justification typology. The findings showed that students used knowledge-based, interpretive, method-based, observation-based, authority-based, and informal knowledge-based justifications at different stages of the modeling process to justify their answers. It was also found that these types of justification were not limited to a specific stage; however, it was determined that justifications become visible with different functions in the stages of understanding the problem, establishing context, creating a mental model, model building-solving, and evaluation. While justifications in the context of mathematics are mostly related to measurement, calculation, selection of operations, and quantitative model building processes, justifications in the context of science are shaped through concepts such as environmental impact, recycling, energy consumption, carbon emissions, and material properties. The results show that interdisciplinary mathematical modeling activities offer a functional learning environment that makes students’ justification processes visible. Accordingly, it is important to design learning environments in modeling activities that support students not only in reaching results but also in justifying solution processes. Considering the limitations of this study, future research should examine the types and functions of justification across different grade levels, disciplinary combinations, and modeling tasks with larger and more diverse participant groups. In addition, using individual interviews, stimulated recall interviews, or other complementary data sources may provide a more comprehensive understanding of students’ individual justification processes, alongside those that emerge during group interactions.