The requirement of large sample sizes for calibrating items based on item response theory (IRT) models is not easily met in many practical pretesting situations. Although classical item statistics could be estimated with much smaller samples, the values may not be comparable across different groups of examinees. This study extended the authors'…

This study compared classical test theory (CTT) and item response theory (IRT). The behavior of the item and person statistics derived from these two measurement frameworks was examined analytically and empirically using a data set obtained from BILOG (R. Mislay and D. Block, 1997). The example was a 15-item test with a sample size of 600…

In the reporting of individual student results from standardized tests in educational assessments, the percentile rank of the individual student is a major numerical indicator. This paper develops a formulation and presents calculations to examine the accuracy of the individual percentile rank score. Here, accuracy follows the common-sense…

Classical test theory is based on the concept of a true score for each examinee, defined as the expected or average score across an infinite number of repeated parallel tests. In most cases, there is only a score from a single administration of the test in question. The difference between this single observed score and the underlying true score is…

Various models have been proposed for analyzing dichotomous test or questionnaire items which were constructed to reflect an assumed underlying structure (e.g., hierarchical). This paper shows that many such models are special cases of latent class analysis and discusses a currently available computer program to analyze them. (Author/JKS)

The Triangular Constant Method was designed for the measurement of discriminability between sensory stimuli. Its original model assumes a steady excitatory detection state. The purpose of this paper is to elaborate on the consequences of assuming a variable exicitatory state and to formulate the concomitant model. (Author)

Both the binomial and beta-binomial models are applied to various problems occurring in mental test theory. The paper reviews and critiques these models. The emphasis is on the extensions of the models that have been proposed in recent years, and that might not be familiar to many educators. (Author)

Describes a procedure for rescaling objective measures of comprehension so that they reflect amounts of accuracy of comprehension on an absolute scale. Suggests there is adequate empirical evidence supporting the validity of the rauding rescaling procedure. (RS)

Investigated the overlap between the Wechsler Intelligence Scale for Children - Revised (WISC-R) and the Halstead-Reitan Neuropsychological Battery (HRNB) in light of their use in diagnosing children's learning problems using scores for children (N=1,181) on the WISC-R and the HRNB. Results showed primary overlap between measures was attributed to…

A historical perspective is provided of the concept of invariance in measurement theory, describing sample-invariant item calibration and item-invariant measurement of individuals. Invariance as a key measurement concept is illustrated through the measurement theories of E. L. Thorndike, L. L. Thurstone, and G. Rasch. (SLD)

Examines the relationship between Cronbach's coefficient alpha and the reliability of a composite of a prespecified set of interrelated nonhomogeneous components through simulation. Shows that alpha can over- or underestimate scale reliability at the population level. Illustrates the bias in terms of structural parameters. (SLD)

Compared classical test theory (CTT), generalizability theory (GT), and multifaceted Rasch model (MFRM) approaches to detecting and correcting for rater variability using responses of 4,930 high school students graded by 3 raters on 9 scales. The MFRM approach identified far more raters as different than did the CTT analysis. GT and Rasch…

The history of generalizability theory (G theory) is told from the perspective of one researcher's experiences, describing psychometric and scientific perspectives that influenced the development of G theory and its adoption. Work that remains to be done in the field is outlined. (SLD)

Introduces a new Item Response Theory (IRT) based statistic for detecting answer copying. Compares this omega statistic with the best classical test theory-based statistic under various conditions, and finds omega superior based on Type I error rate and power. (SLD)

A decision-theoretic approach to the question of reliability in categorically scored examinations is explored. The concepts of true scores and errors are discussed as they deviate from conventional psychometric definitions and measurement error in categorical scores is cast in terms of misclassifications. A reliability measure based on…