Educational tests often have a cluster of items linked by a common stimulus ("testlet"). In such a design, the dependencies caused between items are called "testlet effects." In particular, the directional testlet effect (DTE) refers to a recursive influence whereby responses to earlier items can positively or negatively affect…

Response styles pose great threats to psychological measurements. This research compares IRTree models and anchoring vignettes in addressing response styles and estimating the target traits. It also explores the potential of combining them at the item level and total-score level (ratios of extreme and middle responses to vignettes). Four models…

Sometimes, test-takers may not be able to attempt all items to the best of their ability (with full effort) due to personal factors (e.g., low motivation) or testing conditions (e.g., time limit), resulting in poor performances on certain items, especially those located toward the end of a test. Standard item response theory (IRT) models fail to…

A practical concern for many existing tests is that subscore test lengths are too short to provide reliable and meaningful measurement. A possible method of improving the subscale reliability and validity would be to make use of collateral information provided by items from other subscales of the same test. To this end, the purpose of this article…

Structural equation models of the same construct collected on different occasions are evaluated in 2 studies involving the evaluation of 157 college instructors over 8 years and data for over 2,200 high school students over 4 years for the Youth in Transition Study. Results challenge overreliance on simplex models. (SLD)

An index for the dependability of mastery tests is described. Assumptions necessary for the index and the mathematical development of the index are provided. (Author/JKS)

Within the beta-binomial Bayesian framework, procedures are described for the evaluation of the kappa index of reliability on the basis of one administration of a domain-referenced test. Major factors affecting this index include cutoff score, test score variability and test length. Empirical data which substantiate some theoretical trends deduced…

A number of different reliability coefficients have recently been proposed for tests used to differentiate between groups such as masters and nonmasters. One promising index is the proportion of students in a class that are consistently assigned to the same mastery group across two testings. The present paper proposes a single test administration…

This article presents a non-mathematical introduction to latent trait test models and some of their features. Latent trait models are compared to classical test models. Two promising applications of latent trait models and available computer programs are discussed. (Author/JKS)

This article explains the Rasch model for sample-free item analysis and test-free person measurement. It shows how to estimate model parameters from data and how to evaluate the statistical fit of these estimates to the data. Attention is paid to practical considerations. (Author/JKS)

Huynh (1976) suggested a method of approximating the reliability coefficient of a mastery test. The present study examines the accuracy of Huynh's approximation and also describes a computationally simpler approximation which appears to be generally more accurate than the former. (Author/RL)

A variety of practical applications of item characteristic curve test theory are discussed. Among these applications are tailored testing, two stage testing, determining whether two tests measure the same latent trait, and measuring item bias towards minority or other groups. (Author/JKS)

A debate concerning specific issues and the general usefulness of the Rasch latent trait test model is continued. Methods of estimation, necessary sample size, and the applicability of the model are discussed. (JKS)

An important determinant of equating process efficiency is the correlation between the anchor test and components of each form. Use of some monotonic function of this correlation as a measure of equating efficiency is suggested. A model relating anchor test length and test reliability to this measure of efficiency is presented. (Author/DWH)