Modern test theory
Modern test theory models are techniques to assess the psychometric
characteristics of an instrument, focused on the dimensionality of the
questionnaire 5,25. It provides item-specific
information and avoids weight bias owing to subjective allocation of
each item (also known as differential item functioning)5,25.
IRT is composed of associated mathematical models that models the
relation between the latent trait and the item responses26. IRT examines latent trait estimates that do not
vary with the characteristics of the population, also, estimates item
difficulty and discrimination, and determines if response categories are
ordered properly and function as intended 27.