Classical test theory

Abstract

The term Classical Test Theory (CTT) is used colloquially to differentiate Item Response Theory (IRT) and the assessment topics that preceded it. However, CTT covers a wide range of psychometric measurement issues that developed into the formulation of contemporary assessment practices. Formalizing the relationship between latent construct and observed performance, CTT seeks to define test scores as a function of latent trait true scores, error and measurement attributes. CTT models are understood as special cases of the family of generalized linear latent models, and are therefore related, among others, to models of factor analysis, structural equation modeling and IRT.