Detection of differential item functioning in PISA 2022 mathematics test using the Rasch tree method

The purpose of this study is to detect differential item functioning (DIF) and its underlying causes within the mathematics domain of PISA 2022, employing the Rasch tree method. The two subtests, MTB002 and MTB004, were chosen, focusing on response data from Korean students to identify and examine DIF. The findings revealed that educational context variables, including socioeconomic status, family educational support, and school quality, significantly influenced DIF. Moreover, the observed variations in DIF across common items between the two subtests demonstrated that DIF characteristics can differ depending on item context, content knowledge, and problem-solving processes. This study emphasizes the significance of the Rasch tree method as a robust, data-driven tool for subgroup exploration without the need for predefined classifications, offering practical implications for enhancing the fairness of assessment tools and advancing educational environments.