Item Attributes Analysis of Computer-based Test based on IRT

Abstract

The IRT (Item Response Theory) has been studied and applied in computer-based test for decades. However, almost of all these existing IRT studies pay their attentions only on test questions in text-based (or static text/graphic) type of presentation form. In this paper, The study proposed an IDEA model, develped test questions both in text-based and multimedia types of presentation form which have the same semantic meanings, and launched an experiment. This study analyzed the difference of item attributes (i.e., difficulty index, discriminatory power), item information and test score. The result indicated that the difficulty indexes of most interactive multimedia questions are less than those of their corresponding static text/graphic questions. But the static text/graphic presentation questions significantly have better discrimination power as compared with the interactive multimedia presentation questions.