Mr. Ahmad Taiseer Ashour أ. أحمد تيسير عاشور, and Prof. Nedal Kamal Al-Shraifin أ. د. نضال كمال الشريفين. “The Effect of the Percentages of Missing Data of Anchor Test Form Including the Methods of Imputation for Lower and Upper Levels of a Test in the Accuracy of Estimated Parameters of the Ability and Items”. Journal of Al-Quds Open University for Educational & Psychological Research & Studies 10, no. 27 (June 9, 2019). Accessed July 3, 2024. https://journals.qou.edu/index.php/nafsia/article/view/2007.