This paper deals with the importance of the error measurement both in the Classical Test Theory and in the Item Response Theory (IRT) and about some aspects related to the estimation of the proficiencies under the IRT logistic models. The paper shows that only in the 3 parameter model, the consistency of the response pattern affects the estimation of the proficiencies. The paper also shows the importance of having adequate tests to the student or population.
Classical Test Theory; Item Response Theory (IRT); Measurement error; Proficiency; Maximum Likelihood Estimator (MLE); Expected a Posteriori Estimator (EAP); Response pattern
