Andriani, F., Indrowati, M. and Sugiharto, B. 2021. Analysis items of the four-tier immune system multiple choice test instrument using rasch model. Biosfer: Jurnal Pendidikan Biologi. 14, 1 (Apr. 2021), 99-119. DOI:https://doi.org/10.21009/biosferjpb.18020.