Development of a STEM-based argumentation ability assessment instrument for university students within the independent curriculum

In Indonesia's Independent Curriculum era, universities are expected to help students develop critical thinking and problem-solving skills through interdisciplinary learning. One key skill that students, especially in STEM (Science, Technology, Engineering, and Mathematics) fields, need to develop is argumentation. This includes logical reasoning, using evidence to support claims, and engaging in scientific discussions. However, current assessment tools often do not fully measure students’ argumentation skills in STEM areas. This study aims to develop a STEM-based argumentation ability instrument using Item Response Theory (IRT). The content validity of the instrument was examined through a Focus Group Discussion with five experts, and its scoring was reviewed by seven panel members. Construct validity was tested in two stages: a small-scale trial with 15 students and a larger test with 42 students from two classes. The Rasch Model was used to analyze the instrument's validity and reliability. All items fit the Rasch Model, showing that the instrument is both valid and reliable. Therefore, it can be used to assess university students' STEM-based argumentation skills within the Independent Curriculum.