Selection of test items is a vital step in test development procedure. Test items could be selected either through the item card or Item Characteristic Curve (ICC). In recent times ICC, has become a vital tool in the selection of tests items as it shows graphically the psychometric properties of the test items. At a glance the curve gives such information as discriminating, difficulty and guessing value (depending on the model). This study works on modeling of 2- parameter model of Item Response Theory (IRT) to generate the item characteristics curve using a software in addition to the windows Microsoft excel application. It also involves a do-it-yourself guide using the windows excel application.The experimental result shows that the ICC curve could be a vital tool in determining the suitability of item for section in a test.
Keywords: 2-parameter model, ICC, IRT, difficulty index., discrimination index
