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…

The equity properties can be used to assess the quality of an equating. The degree to which expected scores conditional on ability are similar between test forms is referred to as first-order equity. Second-order equity is the degree to which conditional standard errors of measurement are similar between test forms after equating. The purpose of…

The assessment of positive affect (PA) and negative affect (NA) by means of the Positive Affect and Negative Affect Schedule has received a remarkable popularity in the social sciences. Using a meta-analytic tool--namely, reliability generalization (RG)--population reliability scores of both scales have been investigated on the basis of a random…

Longitudinal studies are permeating clinical trials in psychiatry. Therefore, it is of utmost importance to study the psychometric properties of rating scales, frequently used in these trials, within a longitudinal framework. However, intrasubject serial correlation and memory effects are problematic issues often encountered in longitudinal data.…

The distinction between two models of reliability is clarified. Reliability may be conceived of and estimated from a true score model or from the perspective of sampling precision. Basic models are developed and illustrated for each approach using data from the author's work on measuring organizational climate. (SLD)

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…

A model-based approach to rater reliability for essays read by multiple readers is presented. Variation of rater severity (between-rater variation) and rater inconsistency (within-rater variation) is considered in the presence of between-examinee variation. An additive variance component model is posited and the method of moments for its…

A Paradigm for testing concept attainment, comprised of twelve tasks, was formulated. These tasks were hypothesized to form a cumulative hierarchy. Tests were constructed in mathematics and social studies using the paradigm. Data for these tests was analyzed by Kaiser's method for fitting a perfect simplex and Schonemann's method for fitting a…

Racial differences in the reporting accuracy of parental status characteristics by White and Black high school seniors were investigated using Joreskog's general framework for simultaneous covariance structure analyses of multiple populations. Reliability estimates for Whites were significantly higher than for Blacks due to differences in true…