Current procedures for equating number-correct scores using traditional item response theory (IRT) methods assume local independence. However, when tests are constructed using testlets, one concern is the violation of the local item independence assumption. The testlet response theory (TRT) model is one way to accommodate local item dependence.…

The frequently neglected and often misunderstood relationship between classical test theory and item response theory is discussed for the unidimensional case with binary measures and no guessing. It is pointed out that popular item response models can be directly obtained from classical test theory-based models by accounting for the discrete…

This paper is aimed at demonstrating that Charles Spearman postulated neither a platonic true-error distinction nor a requirement for constant true scores under repeated measurement. (Author/RC)

According to classical test theory, the presence of random measurement error in a psychological test has important implications for validation studies. The more comprehensive application of classical test theory in construct validation is distinguished from that in criterion-oriented validation. Critics of thematic apperceptive measurement of the…