Sampling errors limit the accuracy with which forms can be linked. Limitations on accuracy are especially important in testing programs in which a very large number of forms are employed. Standard inequalities in mathematical statistics may be used to establish lower bounds on the achievable inking accuracy. To illustrate results, a variety of…

The focus of this presidential address is on the contemporary treatment of reliability and validity in educational assessment. Highlights on reliability are provided under the classical true-score model using tools from latent trait modeling to clarify important assumptions and procedures for reliability estimation. In addition to reliability,…

A method for selecting between K-dimensional linear factor models and (K + 1)-class latent profile models is proposed. In particular, it is shown that the conditional covariances of observed variables are constant under factor models but nonlinear functions of the conditioning variable under latent profile models. The performance of a convenient…

This paper complements previous studies on the effects of health on wages by addressing the problems of unobserved heterogeneity, sample selection, and endogeneity in one comprehensive framework. Using data from the German Socio-Economic Panel (GSOEP), we find the health variable to suffer from measurement error and a number of tests provide…

Theoretical models specifying indirect or mediated effects are common in the social sciences. An indirect effect exists when an independent variable's influence on the dependent variable is mediated through an intervening variable. Classic approaches to assessing such mediational hypotheses (Baron & Kenny, 1986; Sobel, 1982) have in recent years…

A latent variable analysis procedure for evaluation of reliability coefficients for 2-level models is outlined. The method provides point and interval estimates of group means' reliability, overall reliability of means, and conditional reliability. In addition, the approach can be used to test simple hypotheses about these parameters. The…

Most of the statistical procedures in meta-analysis are based on the estimation of average effect sizes from a set of primary studies. The optimal weight for averaging a set of independent effect sizes is the inverse variance of each effect size, but in practice these weights have to be estimated, being affected by sampling error. When assuming a…

This article provides a conceptual introduction to the issues surrounding the analysis of clustered (nested) data. We define the intraclass correlation coefficient (ICC) and the design effect, and we explain their effect on the standard error. When the ICC is greater than 0, then the design effect is greater than 1. In such a scenario, the…

As the United States becomes more racially and ethnically diverse and draws more students from across the globe, more representative data are needed to understand at-risk and underrepresented populations in higher education, particularly in the science, technology, engineering, and mathematics (STEM) fields. The authors argue that the current…

Test-based accountability as well as value-added asessments and much experimental and quasi-experimental research in education rely on achievement tests to measure student skills and knowledge. Yet, we know little regarding fundamental properties of these tests, an important example being the extent of measurement error and its implications for…

Quantum mechanics is often thought to be a difficult subject to understand, not only in the complexity of its mathematics but also in its conceptual foundation. In this paper we emphasize students' depictions of the uncertainty principle and wave-particle duality of quantum events, phenomena that could serve as a foundation in building an…

Non-exercise equations developed from self-reported physical activity can estimate maximal oxygen uptake (VO[subscript 2]max) as well as sub-maximal exercise testing. The International Physical Activity Questionnaire is the most widely used and validated self-report measure of physical activity. This study aimed to develop and test a VO[subscript…

To realize the benefits of item response theory (IRT), one must have model-data fit. One facet of a model-data fit investigation involves assessing the tenability of the conditional item independence (CII) assumption. In this Monte Carlo study, the comparative performance of 10 indices for identifying conditional item dependence is assessed. The…

ABILHAND is, in its original version, a 46-item, 4-level questionnaire. It measures the difficulty perceived by patients with rheumatoid arthritis as they do various daily manual tasks. ABILHAND was originally built through Rasch analysis. In a later study, it was simplified to a generic 23-item, three-level questionnaire, showing both…

A new form of composition of the indicators employed to generate the United Nations Human Development Index (HDI) is presented here. This form of composition is based on the assumption that random errors affect the measurement of each indicator. This assumption allows for replacing the vector of evaluations according to each indicator by vectors…