Research article
Calibrating PIRLS Test in Sultanate of Oman Using Item Response Theory
The study aimed to calibrate Oman data of the PIRLS test using the graded response model and to examine the psychometric properties of it, as well as identify the fit and unfit of its items. PIRLS2011 test booklets were used, which consisted of 146 test items (74 dichotomous and 72 polytomous). Items were divided into …