STEM-Focused Science Identity Questionnaire Based on the PISA 2025 Framework: Rasch Model Validation

This study developed and validated a Science Identity Questionnaire for secondary school students based on the PISA 2025 framework using a Rasch model analysis. The questionnaire aimed to measure key aspects of science identity, including science capital, attitude toward science, and environmental awareness. A total of 496 students (200 males and 269 females) from various Indonesian provinces participated. The data were analyzed using the Rasch model to examine item validity, reliability, and demographic bias. The results indicated that the questionnaire fit the Rasch model excellently, confirming its validity, with Outfit and Infit Mean Square values within acceptable ranges. Reliability analysis yielded person and item reliabilities of 0.72 and 0.99, respectively. No significant bias was detected between male and female students or between urban and rural respondents. These findings support using this tool to assess science identity and its role in promoting long-term STEM engagement. This instrument can inform interventions that aim to foster inclusive science education.