An Introduction to the Modern Approach in Educational and Psychological Measurement

Nowadays, there are two dominant paradigms in the measurement domain: the Classic Theory of Measurement introduced by Spearman and item-Response Theory whose genesis can be traced to the latent Trait Theory. In fact, once used for the measuring variables with two levels, the latent theory was dubbed Item-Response Theory. This theory has clear and rational foundation though its intricate mathematical underpinning - compared to the classical theory - has caused researchers to have little inclination to use it. Within the framework of this theory, there are two different approaches to measurement. The first approach which adheres to the Rosh models aims at measuring the magnitude of the target trait in people. However, the second approach, which has developed with the primary purpose of analyzing questions and evaluating their parameters. draws on the parametric models of 2 and 3 for achieving the same objective. Despite all the differences between these two approaches, researchers are mostly unaware of them with ve,y few sources pinpointing the discrepancies. Therefore, the current study deals with the theoretical foundations of the item-response theory, its assumptions, as well as its models and their differences.