Collaboration is a complex skill, comprised of multiple subskills, that is of growing interest to policy makers, educators and researchers. Several definitions and frameworks have been described in the literature to support assessment of collaboration; however, the inherent structure of the construct still needs better definition. In 2015, the…

The effect of violating the assumption of nonspeededness on ability and item parameter estimates in item response theory was studied through simulation under three speededness conditions. Results indicate that ability estimation was least affected by speededness but that substantial effects on item parameter estimates were found. (SLD)

The nonparametric Mokken model of test data was compared with parametric models using simulated data through latent class analysis. It is demonstrated that latent class analysis provides a consistent comparison of item response models. (SLD)

How item bias indexes based on item response theory (IRT) identify bias that results from multidimensionality is demonstrated. Simulation results suggest that IRT-based bias indexes detect multidimensional items with bias but do not detect multidimensional items without bias. They also do not confound between-group differences on the primary test.…

The goal of this study was the development of a procedure to predict the equating error associated with the long-term equating method of Tate (2003) for mixed-format tests. An expression for the determination of the error of an equating based on multiple links using the error for the component links was derived and illustrated with simulated data.…

The equating of results from the PC-BILOG computer program to an underlying metric was studied through simulation when a two-parameter item response theory model was used. Results are discussed in terms of the identification problem and implications for test equating. (SLD)

The capability of the DIMTEST statistical test to assess essential dimensionality of the model underlying item responses of real tests as opposed to simulated tests was investigated. A variety of real test data from difference sources was used to assess essential dimensionality. Based on DIMTEST results, some test data are assessed as fitting an…

A statistical procedure is presented that is designed to test for unidirectional test bias existing simultaneously in several items of an ability test, based on the assumption that test bias is incipient within the two groups' ability differences. The proposed procedure--Simultaneous Item Bias (SIB)--is based on a multidimensional item response…

Smallest exact confidence intervals for the ability parameter of the Rasch model are derived and compared to the traditional asymptotically valid intervals based on Fisher information. Tables of exact confidence intervals, termed Clopper-Pearson intervals, can be drawn up with a computer program developed by K. Klauer. (SLD)

The adequacy of multidimensional trait and item parameters using multidimensional item response theory analysis was studied through simulation using different degrees of correlation between two trait dimensions and the existence of a restricted trait on the second dimension. Conditions allowing adequate recovery of trait and item parameters are…

An item response theory-based parametric procedure proposed by N. S. Raju, W. J. van der Linden, and P. F. Fleer (1995) known as differential functioning of items and tests (DFIT) can be used with unidimensional and multidimensional data with dichotomous or polytomous scoring. This study describes the polytomous DFIT framework and evaluates and…

The Mantel-Haenszel (MH) procedure has become one of the most popular procedures for detecting differential item functioning (DIF). One of the most troublesome criticisms of this procedure is that while detection rates for uniform DIF are very good, the procedure is not sensitive to non-uniform DIF. In this study, examinee responses were generated…

The assessment of dimensionality of data is important to item response theory (IRT) modelling and other multidimensional data analysis techniques. The fact that the parameters from the factor analysis formulation for dichotomous data can be expressed in terms of the parameters in the multidimensional IRT model suggests that the assessment of the…

Describes algorithms used in the computer program LOGIMO for obtaining maximum likelihood estimates of the parameters in loglinear models. These algorithms are also useful for the analysis of loglinear item-response theory models. Presents modified versions of the iterative proportional fitting and Newton-Raphson algorithms. Simulated data…

Investigates the BILOG computer program's ability to recover known item parameters for different numbers of items, examinees, and variances of the prior distributions of discrimination parameters for the two-parameter logistic item-response theory model. For samples of at least 250 examinees and 15 items, simulation results support using BILOG.…