Item Difficulty and Item Discrimination Coefficient for School and College Ability Tests (SCAT) Advanced Form in Classical Test Theory (CTT) and Item Response Theory (IRT) and the Correlation among Them. jperc [Internet]. 2018 Jul. 1 [cited 2025 May 4];15(58):72-9. Available from: https://jperc.uobaghdad.edu.iq/index.php/jperc/article/view/2032