The Bologna Declaration brought reforms into higher education that imply changes in teaching methods, didactic materials and textbooks, infrastructures and laboratories, etc. Statistics and mathematics are disciplines that traditionally have the worst success rates, particularly in non-mathematics core curricula courses. This research project,…

Two versions of a general method for approximating standard error of regression effect estimates within an IRT-based latent regression model are compared. The general method is based on Binder's (1983) approach, accounting for complex samples and finite populations by Taylor series linearization. In contrast, the current National Assessment of…

Traditionally, the fixed-length linear paper-and-pencil (P&P) mode of administration has been the standard method of test delivery. With the advancement of technology, however, the popularity of administering tests using adaptive methods like computerized adaptive testing (CAT) and multistage testing (MST) has grown in the field of measurement…

Numerous studies have shown increasing item reliabilities as an effect of the item position in personality scales. Traditionally, these context effects are analyzed based on item-total correlations. This approach neglects that trends in item reliabilities can be caused either by an increase in true score variance or by a decrease in error…

Background: Relatively little is known about the genetic architecture of childhood behavioral disorders in very young children. Method: In this study, parents completed the Infant-Toddler Social and Emotional Assessment, a questionnaire that assesses symptoms of childhood disorders, as well as socio-emotional competencies, for 822 twin pairs…

A procedure for checking the score equivalence of nearly identical editions of a test is described. The procedure employs the standard error of equating (SEE) and utilizes graphical representation of score conversion deviation from the identity function in standard error units. Two illustrations of the procedure involving Scholastic Aptitude Test…

The purpose of this study was to examine the effect of test dimensionality on the stability of examinee ability estimates and item response theory (IRT) based score reports. A simulation procedure based on W. F. Stout's Essential Unidimensionality was used to generate test data with one dominant trait for the whole test and three minor traits…

The use of a covariate for randomized response (RRT) research has been shown to reduce standard errors of sensitive trait proportion estimates. At the same time, the model has been shown to be subject to serious misspecification when the relationship between the covariate and the sensitive trait is non-monotonic. The RRT covariate model is adapted…

Logistic regression was used for modeling the observation-to-indicator ratio needed for the standard error scree procedure (SEscree) to correctly identify the number of factors existing in generated sample correlation matrices. The created correlation matrices were manipulated along the number of factors (4,6), sample size (250, 500), magnitude of…

Educational researchers often use multiple statistical tests in their research studies and program evaluations. When multiple statistical tests are conducted, the chance that Type I errors may be committed increases. Thus, the researchers are faced with the task of adjusting the alpha levels for their individual statistical tests in order to keep…

A probability distribution was developed for the Andrews-Pregibon (AP) statistic. The statistic, developed by D. F. Andrews and D. Pregibon (1978), identifies multivariate outliers. It is a ratio of the determinant of the data matrix with an observation deleted to the determinant of the entire data matrix. Although the AP statistic has been used…

Simulations were performed to verify the accuracy with which the Mantel-Haenszel (MH) and Rasch PROX procedures recover simulated item bias. Several standard error estimators for the MH procedure were evaluated. Item bias is recovered satisfactorily by both techniques under all simulated conditions. The proposed MH standard error estimators have…

A recurring problem in educational research is how to account for non-random selection that has restricted the range of the variables of interest in correlational analyses. Several expressions due to H. Pearson (1903) and presented in matrix notation by D. N. Lawley (1943-44) are commonly used in selection settings to adjust for samples chosen on…

An approximation formula for the standard error of measurement was recently proposed by Garvin. The properties of this approximation to the standard error of measurement are described in this paper and illustrated with hypothetical data. It is concluded that the approximation is a systematic overestimate of the standard error of measurement…

In the light of research by Epstein (1979) (which reported that error of measurement in the analysis of behavior stability may be reduced by examining the behavior of aggregate stability coefficients computed for measurements with known stability characteristics), this study examines stability coefficients for computer-generated data sets…