A Comparison the Information Functions of the Item and Test on One, Two and Three Parametric Model of the Item Response Theory (Irt)

AbstractPresent study sets out to compare test and item function in one-, two-, and three-parameter models in the item response theory (IRT). First, information function is delineated upon drawing on theoretical and psychometric foundations. The date collected from the pool of answers given to multiple-choice questions by candidates to the Iranian state universities who took the National Entrance Examination for State Universities in the Mathematics-Physics Testing Group in 2009 which was administered by the National Organization for Educational Testing (NOET). Systematic sampling was utilized to draw 2000 subjects from applicants who took entrance exam in the Mathematics-Physics Testing Group of National Entrance Examination for State Universities. To analyze the data obtained from experimental group, two statistical software viz. SPSS and BILOG were run. The results yielded indicate that the value of test and item awareness function in the two- parameter model is higher than values in the one-and three –parameter models .Furthermore, findings illustrate that the value of test and item awareness function in the one –parameter models is not significantly different from the corresponding value in the three –parameter model. This study has implications for educational measurement and testing procedures especially for standardized multiple-choice test