Two approaches to psychometric process: Classical test theory and item response theory

Abstract

In the development of Measurement Theory, there are two main statistical approaches to describe characteristics of an individualand to analyze abilities and latent attributes of a subject which are Classical Test Theory (CTT) and Item ResponseTheory (IRT). This study provides information about the essential properties of both theories, determines psychometric processof measurement with details, compares models of theories and obviously expresses the advantages and disadvantages ofboth theories. The earliest theory of measurement, CTT, and the enhanced application of this theory, IRT models are examinedfrom the common and different points of view. This article emphasizes the importance of the constructing, measuring, evaluatingand correctly interpreting the educational measurement process.