Rasch Calibration and Differential Item Functioning (DIF) Analysis of the Indonesian National Assessment Program-Language (INAP-L)

This study aimed to evaluate the psychometric properties of INAP-L instrument by applying Rasch model. The evaluation includes item calibration and differential functioning (DIF) assessment. Participants in this were 6153 high school students (2326 boys 3827 girls) aged 14-19 years (mean age = 15.76, SD 0.78) from 280 schools spread across 34 provinces Indonesia. results model analysis show that assumptions unidimensionality local independence are met. internal consistency (PSR 0.80; Ordinal α 0.81) item-person targeting showed quite good results. At level, it was discovered four forty items did not fit Meanwhile, gender-based DIF revealed all free gender two out based on type. It can be concluded has properties. Furthermore, multilevel performed determine effect clustering data, a data structure with ICC 0.185 design > 2.00. means future research relationship among variables score must consider approach. Even though developer already published an interim report INAP-L, findings used as reference improving before conducting future.